JP2010095561A - Ink for inkjet recording, and inkjet recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink for inkjet recording that exhibits good ink fixability and a good ejection property after a recording head is exposed to the air when printed by an inkjet recording method. <P>SOLUTION: The ink for inkjet recording comprises water, a coloring material and a nonionic surfactant, where 3,6-dithia-1,8-octanediol is contained in an amount of at least 5.0 mass% and at most 11.0 mass%. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an inkjet recording ink and an inkjet recording method.

  An ink jet recording apparatus includes a recording head in which nozzles for ejecting ink are formed, a carriage that carries the recording head and reciprocates, and a recording medium conveyance device that conveys the recording medium in a direction perpendicular to the reciprocating direction. I have.

  An ink jet recording apparatus performs recording by directly ejecting ink from a recording head, and therefore it is necessary to always keep ink in a dischargeable state. Even when the recording head is exposed to the atmosphere without printing for a certain period of time, if the ejection characteristics of the recording head are good, the uniformity is said to be good.

As a method for improving the uniformity, proposals have been made to suppress nozzle clogging due to drying by the composition in the ink for inkjet recording (see Patent Documents 1 and 2).
JP 2004-292817 A JP-A-2005-298609

  The inks described in Patent Documents 1 and 2 are proposals for suppressing nozzle clogging due to water evaporation from the ink, depending on the composition of the ink. These attempt to suppress nozzle clogging by adding diols to the ink.

  However, these inks are inadequate in terms of both the uniformity and fixability.

  Accordingly, an object of the present invention is to provide an ink for ink-jet recording that has both good fixability and good light-emitting properties when printed by the ink-jet recording method.

  The object of the present invention is achieved by the following configurations.

  That is, the present invention is an ink jet recording ink containing water, a coloring material, and a nonionic surfactant, and containing 5.0 mass% or more of 3,6-dithia-1,8-octanediol, An ink for ink-jet recording, characterized by containing 11.0% by mass or less.

  According to another aspect of the present invention, there is provided an ink jet recording method including a step of ejecting the ink toward a recording medium and attaching the ink to the recording medium.

  According to the present invention, it is possible to provide an ink for ink jet recording and an ink jet recording method in which both the fixing property and the light emission of the ink are good.

  Hereinafter, the present invention will be described in more detail with reference to preferred embodiments.

  Examples of the color material used in the ink jet recording ink of the present invention include dyes and pigments.

  As the dye, the following dyes are preferably used. For example, C.I. I. Direct black 17, 19, 32, 51, 62, 71, 108, 146, 154. C. I. Direct blue 6, 22, 25, 71, 86, 90, 106, 199. C. I. Direct red 1, 4, 17, 28, 83. C. I. Direct yellow 12, 24, 26, 44, 86, 98, 100, 132, 142. C. I. Direct orange 34, 39, 44, 46, 60. C. I. Direct violet 47, 48. C. I. Direct brown 109. C. I. Direct dyes such as Direct Green 59. C. I. Acid Black 2, 7, 24, 26, 31, 52, 63, 112, 118. C. I. Acid Blue 9, 22, 40, 59, 93, 102, 104, 113, 117, 120, 167, 229, 234, 254. C. I. Acid Red 1, 6, 8, 32, 37, 51, 52, 80, 85, 87, 92, 94, 115, 180, 256, 317, 315. C. I. Acid Yellow 11, 17, 23, 25, 29, 42, 49, 61, 71. C. I. Acid Orange 7, 19. C. I. Acid dyes such as Acid Violet 49. C. I. Reactive Yellow 2, 3, 13, 15, 17, 18, 23, 24, 37, 42, 57, 58, 64, 75, 76, 77, 79, 81, 84, 85, 87, 88, 91, 92 93, 95. 102, 111, 115, 116, 130, 131, 132, 133, 135, 136, 137, 139, 140, 142, 143, 144, 145, 146, 147, 148, 151, 162, 163 . C. I. Reactive Orange 5, 7, 11, 12, 13, 15, 16, 35, 45, 46, 56, 62, 70, 72, 74, 82, 84, 87, 91, 92, 93, 95, 97, 99 . C. I. Reactive Red 3, 13, 16, 21, 22, 23, 24, 29, 31, 33, 35, 45, 49, 55, 63, 85. 106, 109, 111, 112, 113, 114, 118, 126 128, 130, 131, 141, 151, 170, 171, 174, 176, 177, 183, 184, 186, 187, 188, 190, 193, 194, 195, 196. 200, 201, 202, 204, 206 218, 221. C. I. Reactive violet 1, 4, 5, 6, 22, 24, 33, 36, 38. C. I. Reactive Blue 2, 3, 5, 8, 10, 13, 14, 15, 18, 19, 21, 25, 27, 28, 38, 39, 40, 41, 49, 52, 63, 71, 72, 74 75, 77, 78, 78, 89. 100, 101, 104, 105, 119, 122, 147, 158, 160, 162, 166, 169, 170, 171, 172, 173, 174, 176, 179, 184 190, 191, 194, 195, 198. 204, 211, 216, 217. C. I. Reactive Green 5, 8, 12, 15, 19, 23. C. I. Reactive Brown 2, 7, 8, 9, 11, 16, 17, 18, 21, 24, 26, 31, 32, 33. C. I. Reactive dyes such as Reactive Black 1, 5, 8, 13, 14, 23, 31, 34, 39. C. I. Basic Black 2. C. I. Inkjet Black286. C. I. Basic blue 1, 3, 5, 7, 9, 24, 25, 26, 28, 29. C. I. Basic Red 1, 2, 9, 12, 13, 14, 37. C. I. Basic violet 7, 14, 27. C. I. Food black 1,2. Among these, it is preferable to use a direct dye, an acid dye, or a reactive dye.

  As the pigment, the following pigments are preferably used. Examples of pigments used in black ink include No. 2300, no. 900, MCF88, No. 40, no. 52, MA7, MA8, no. 2200B (Made by Mitsubishi Kasei). RAVEN 1255 (made in Colombia). REGAL 400R, REGAL 660R, MOGUL L (above, manufactured by Cabot). Color Black FW1 and 18, Color Black S170 and 150, Printex 35, U (manufactured by Degussa) and the like. Examples of pigments used in yellow ink include C.I. I. Pigment Yellow 1, 2, 3, 13, 16, 74, 83, 93, 128, 134, 144, and the like. Examples of pigments used in magenta ink include C.I. I. Pigment Red 5, 7, 12, 48 (Ca), 48 (Mn), 57 (Ca), 112, 122, C.I. I. Pigment Violet 19 etc. Examples of pigments used for cyan ink include C.I. I. Pigment Blue 1, 2, 3, 15: 3, 16, 22, C.I. I. Vat Blue 4, 6, etc.

  The pigments of any color are preferably used in a form in which dispersibility in water is sufficiently ensured. As such a form, for example, a hydrophilic group such as a carboxylate is provided on the surface of the pigment. Alternatively, a water-soluble resin having a weight average molecular weight in the range of 1,000 to 30,000, such as styrene, a styrene derivative, vinyl naphthalene, and a vinyl naphthalene derivative. Hydrophobic monomers such as aliphatic alcohol esters of α, β-ethylenically unsaturated carboxylic acids. Acrylic acid and acrylic acid derivatives. Maleic acid, maleic acid derivative. Itaconic acid, itaconic acid derivative. Fumaric acid, fumaric acid derivative. It is mentioned that a block copolymer, a graft copolymer, a random copolymer, or a salt thereof composed of two or more monomers selected from the above are attached or bonded.

  The amount of the color material contained in the inkjet recording ink of the present invention is preferably 3% by mass or more and 9% by mass or less with respect to the total amount of the ink. Moreover, it is preferable that it is 5 mass% or less from the point of the uniformity.

  The ink for ink jet recording of the present invention is characterized by containing 3,6-dithia-1,8-octanediol. When the ink contains 3,6-dithia-1,8-octanediol, the ejection becomes stable and the light emission is improved. The reason for this is unknown, but according to the study by the present inventors, 3,6-dithia-1,8-octanediol has a low dye solubility, so that the concentration of the dye in the ink is suppressed, and the ejection It is thought that is stable and has good uniformity.

  The ink of the present invention contains 5.0% by mass or more and 11.0% by mass or less of 3,6-dithia-1,8-octanediol. Moreover, from the point of the uniformity, it is preferable that it is 7.0 mass% or more, and it is more preferable that it is 9.5 mass% or more. Similarly, it is preferably 10.5% by mass or less in terms of uniformity.

  The ink of the present invention contains a nonionic surfactant. As the nonionic surfactant contained in the ink of the present invention, the following are preferable.

  For example, 3,5-dimethyl-1-hexyne-3ol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6- Diol. Ethylene oxide adduct of acetylene glycol (for example, acetylenol EH; manufactured by Kawaken Fine Chemical). Ethylene oxide adduct of acetylene alcohol (for example, acetylenol EL; manufactured by Kawaken Fine Chemical). Ethylene oxide adducts of acetylene or alkanes (eg, Surfinol 104, 82, 465, 485; manufactured by Air Products). Tergitol 15-S-5, Tergitol 15-S-7 (both manufactured by Union Carbide Company). Nonionic surfactants such as those mentioned above can be mentioned. The nonionic surfactant is preferably contained in an amount of 0.1% by mass or more based on the total amount of the ink. Moreover, it is preferable to contain 10.0 mass% or less.

In the ink of the present invention, when the content of 3,6-dithia-1,8-octanediol is a mass% and the content of the nonionic surfactant is b mass% with respect to the total amount of the ink, A and b are
4.7 <a / b <18.4
It is preferable to satisfy the relationship. Even if the nonionic surfactant is contained in a critical micelle concentration or more, the fixability is not further improved. Furthermore, if the content of the nonionic surfactant is excessively increased with respect to the content of 3,6-dithia-1,8-octanediol, the non-volatile component may be increased, thereby deteriorating the uniformity. Therefore, it is preferable to satisfy 4.7 <a / b. Moreover, it is more preferable to satisfy | fill 8.3 <a / b, and it is still more preferable to satisfy | fill 15.0 <a / b. If the amount of the nonionic surfactant is too small relative to the content of the compound represented by the general formula (1), it is difficult to obtain good fixability. Therefore, it is preferable that a / b <18.4 is satisfied.

  Furthermore, the ink of the present invention may contain a water-soluble organic solvent. As the water-soluble organic solvent, the following are preferable. For example, C1-C4 alkyl alcohols, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol. Amides such as dimethylformamide and dimethylacedamide. Ketones or ketone alcohols such as acetone and diacetone alcohol; Ethers such as tetrahydrofuran and dioxane. Polyalkylene glycols such as polyethylene glycol and polypropylene glycol. Alkylene glycols such as ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol, and diethylene glycol; Glycerin; lower alkyl ethers of polyhydric alcohols such as ethylene glycol methyl (or ethyl) ether, diethylene glycol methyl (or ethyl) ether, triethylene glycol monomethyl (or ethyl) ether. N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, triethanolamine, sulfolane and the like. The water-soluble organic solvent as mentioned above is mentioned. Among these, it is preferable to contain a polyhydric alcohol such as diethylene glycol and a lower alkyl ether of a polyhydric alcohol such as triethylene glycol monomethyl (or ethyl) ether. The lower alcohol means an alcohol having 1 to 5 carbon atoms. The content of the water-soluble organic solvent in the ink is preferably 20% by mass or less, and more preferably 10% by mass or less based on the total amount of the ink.

  The ink of the present invention contains water. As water, it is preferable to use deionized water instead of general water containing various ions.

  In addition, the ink of the present invention may further contain an antifungal agent such as proxel, a pH adjuster and the like.

  Hereinafter, although it demonstrates more concretely using an Example and a comparative example, this invention is not limited by the following Example, unless the summary is exceeded. In the following description, “%” is based on mass unless otherwise specified.

<Preparation of ink>
Each component shown in Tables 1 to 3 was mixed and pressure filtered through a membrane filter having a pore size of 0.22 μm to prepare each ink. Each ink is prepared so that the total is 100%. Further, “nonionic surfactants” in the table are all Surfinol 465 (produced by Air Products) which is an ethylene oxide adduct of acetylene. “A / b” in the table means that the content of 3,6-dithia-1,8-octanediol in the ink is a% and the content of the nonionic surfactant is b%. Is the value of

  An ink in which the ink of Example 7 contains 10.0% of diethylene glycol is referred to as Example 11. (Direct Yellow 132; 6.0%, 3,6-dithia-1,8-octanediol; 10.0%, nonionic surfactant; 0.6%, diethylene glycol; 10.0%, water; balance) .

<Evaluation of uniqueness>
A Pixus 950i (4 nozzle rows (cyan, magenta, yellow, black) recording head, ejection amount: 2 pl, nozzle pitch: 300 dpi, number of nozzles in one row: 256, manufactured by Canon) was used as the ink jet recording apparatus. The inks of Examples 1 to 11 and Comparative Examples 1 to 3 were stored in the ink tank of the ink jet recording apparatus. Next, the inks of Examples 1 to 11 and Comparative Examples 1 to 3 were continuously ejected from the recording head onto professional photo paper PR-101 (manufactured by Canon). After continuous discharge, the discharge was stopped for a certain time (10 seconds, 30 seconds). Thereafter, the ink was discharged again, and the decrease in the discharge speed at that time was evaluated in the following five stages. The ejection speed of the liquid droplets was calculated from the time after ejection and the movement distance with respect to the ink ejected from the recording head by synchronizing the ejection and light emission with a strobe light emission type observation device.
1 ... After 30 seconds of rest, ejection becomes impossible.
2: Discharge is possible after a 30-second pause. After a 10-second pause, the discharge rate falls below 20% of the continuous discharge rate.
3... Can be discharged after 30 seconds rest. After a 10-second pause, the discharge speed decreases to 20% or more and less than 50% of the continuous discharge speed.
4: Discharge is possible after a 30-second pause. After a 10-second pause, the discharge speed decreases to 50% or more and less than 70% of the continuous discharge speed.
5: Discharge is possible after a 30-second pause. After a 10-second pause, the discharge speed is 70% or more of the continuous discharge speed.

<Fixability evaluation>
Pixus 950i (manufactured by Canon) was used as an ink jet recording apparatus. Inks of Examples 1 to 11 and Comparative Examples 1 to 3 were stored in an ink tank of an ink jet recording apparatus, and ink droplets were ejected on a recording medium so that a 5 mm square solid pattern was in a checkered pattern. As the recording medium, White Recycle Paper EW-100 (manufactured by Canon) was used. Further, after 10 seconds from the end of printing, the checkered solid pattern was subjected to a rubbing test with a filter paper. The filter paper is No. 5c (made by Toyo Roshi) was used. Fixability was evaluated according to the following five-stage criteria based on the result of the rubbing test.
5: The checkered solid pattern was not faint.
4 ... The checkered solid pattern was slightly faint but not noticeable.
3 ... The checkered solid pattern was faint.
2 ... The checkerboard-like solid pattern was severely blurred.
1 ... Partial nozzles do not eject droplets.

  The results of the above evaluation are shown in Table 4. In addition, it is a result in the environment of temperature 25 degreeC and humidity 50%.

  Comparing Examples 2 to 8 and Comparative Examples 1 to 3, it can be seen that the ink of the present invention has good light-emitting properties and fixing properties. In addition, when Example 1 and Example 2 are compared, it can be seen that the ink having a lower colorant density has better uniformity. From Examples 2 to 8, the content of 3,6-dithia-1,8-octanediol in the ink is preferably 7.0% by mass or more, and 9.5% by mass from the viewpoint of uniformity. % Is more preferable, and 10.5% by mass or less is preferable. Comparing Example 7 with Examples 10 and 11, it can be seen that the ink of the present invention has good color formation even when the color material is different.

Claims (4)

An ink for ink jet recording containing water, a coloring material, and a nonionic surfactant,
An ink for ink-jet recording, comprising 5.0% by mass or more and 11.0% by mass or less of 3,6-dithia-1,8-octanediol. When the content of 3,6-dithia-1,8-octanediol is a mass% and the content of the nonionic surfactant is b mass% with respect to the total amount of ink, a and b are
4.7 <a / b <18.4
The ink for inkjet recording of Claim 1 satisfy | filling the relationship of these. A and b are
8.3 <a / b <18.4
The ink for inkjet recording of Claim 2 which satisfy | fills the relationship of these.   An ink jet recording method comprising a step of ejecting the ink according to any one of claims 1 to 3 toward a recording medium and attaching the ink to the recording medium.