JP3311332B2 - INK, INK JET RECORDING METHOD USING THE SAME, AND APPARATUS USING THE INK - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink, an ink jet recording method using the ink, and an apparatus using the ink. More specifically, the present invention relates to an ink which gives an image having excellent water resistance even when printed on plain paper. The present invention relates to an ink jet recording method using the same and a device using such an ink.

[0002]

2. Description of the Related Art Inkjet inks of various compositions have been reported. Above all, the composition and physical properties of the ink so that good recording can be performed on plain paper such as copy paper, report paper, notebooks, stationery, bond paper, continuous slip paper, etc., which are generally used in offices in recent years. Detailed research and development has been done from various aspects such as. For example, aqueous inks are generally used for ink-jet recording, but when printing is performed on various types of recording materials using such inks, the coloring material used in the ink is a water-soluble dye. In addition, there is a problem that the printed image is blurred by sweat, water droplets, and the like, and the printed image becomes unclear or damaged.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an ink having excellent water resistance of a printed image even when printing on various types of plain paper, an ink jet recording method using the same,
An object of the present invention is to provide a device using such an ink.

[0004]

The above object is achieved by the present invention described below. That is, the present invention provides an ink containing at least water, a water-soluble organic solvent, and a dye, wherein the dye has a molecular structure represented by the following general formula (1), and the number of sulfonic acid groups and the number of amino groups in one molecule are: An ink containing two or more compounds each having a number of sulfonic acid groups smaller than the number of amino groups (wherein Q _{1 in the} formula (1) is a group selected from NH ₂ and SO ₃ M) Represents a phenyl group, a pyridyl group, or a naphthyl group, and Q ₂ represents CH ₃ , OCH ₃ , NHCOCH ₃
And p-phenylene or 1,4-naphthylene substituted with a group selected from SO ₃ M, and Q ₃ represents an unsubstituted or SO ₃ M-substituted diaminopyridyl, or CO 3
Represents a diaminophenyl group substituted with OM or SO ₃ M, M represents an alkali metal, ammonium or organic ammonium, and n represents 0 or 1. ), And an ink jet recording method using these inks, and a device using such inks.

[0005]

The present invention mainly employs a compound (dye) having a specific structure as a coloring material of an ink to provide an ink having excellent water resistance of a printed image even when printed on various types of plain paper.
It is possible to provide an ink jet recording method using this, and a device using such an ink.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail with reference to preferred embodiments. The dyes of the general formulas (1) and (2) used in the present invention and which mainly characterize the present invention may be any dyes as long as they are included in these general formulas, and may be used alone or as a mixture. It can be used, and in some cases, may be used in combination with other dyes not included in the above general formula. First, the first aspect of the present invention is, as described above, an ink containing at least water, a water-soluble organic solvent and a dye, which has a molecular structure represented by the general formula (1) as a dye, An ink characterized in that the number of sulfonic acid groups and the number of amino groups are each 2 or more, and the ink contains a compound in which the number of sulfonic acid groups is smaller than the number of amino groups. Particularly preferred dyes among these dyes are as exemplified below.

[0007]

[0008]

[0009]

[0010]

[0011]

[0012]

[0013]

[0014]

The content of the above dye compound in the ink is determined depending on the kind of the liquid medium component, the characteristics required for the ink, etc., but generally about 0% by weight in the total amount of the ink. 0.2 to 20%, preferably 0.5 to 10%, more preferably 1 to 5%.

The liquid medium used in the ink of the present invention is a mixture of water and a water-soluble organic solvent. As the water, not only ordinary water but also preferably deionized water is used. Examples of the organic solvent include methyl alcohol, ethyl alcohol, n
-Propyl alcohol, isopropyl alcohol, n-
Butyl alcohol, sec-butyl alcohol, ter
C1-C5 alkyl alcohols such as t-butyl alcohol, isobutyl alcohol, n-pentanol or halogenated derivatives thereof; dimethylformamide;
Amides such as dimethylacetamide; ketones or ketoalcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol, and polypropylene Oxyethylene or oxypropylene addition polymers such as glycol; ethylene glycol, propylene glycol, trimethylene glycol, butylene glycol,
Alkylene glycols having an alkylene group containing 2 to 6 carbon atoms, such as 1,2,6-hexanetriol and hexylene glycol; thiodiglycol; glycerin; ethylene glycol monomethyl (or ethyl) ether;
Diethylene glycol monomethyl (or ethyl) ether, triethylene glycol monomethyl (or ethyl)
Lower alkyl ethers of polyhydric alcohols such as ether; lower dialkyl ethers of polyhydric alcohols such as triethylene glycol dimethyl (or ethyl) ether and tetraethylene glycol dimethyl (or ethyl) ether; sulfolane, 2-pyrrolidone, N- Methyl-2
-Pyrrolidone, 1,3-dimethyl-2-imidazolidinone and the like. The content of the water-soluble organic solvent is generally 2% to 50% by weight based on the total weight of the ink,
Preferably, it is in the range of 2% to 30%. The above media can be used alone or as a mixture.

The main components of the ink of the present invention are as described above, but other various dispersants, surfactants, viscosity modifiers,
A surface tension adjuster, a fluorescent whitening agent, and the like can be added as needed within a range that does not hinder achievement of the object of the present invention. For example, viscosity modifiers such as polyvinyl alcohol, celluloses, and water-soluble resins; various surfactants such as cation, anion or nonionic; surface tension modifiers such as diethanolamine and triethanolamine;
H adjuster; fungicide;

In order to prepare an ink used in an ink jet recording method of charging the ink, a specific resistance adjuster such as inorganic salts such as lithium chloride, ammonium chloride and sodium chloride is added. Incidentally, the ink of the present invention is particularly suitable when applied to an ink jet recording method of a type in which the ink is ejected by a bubbling phenomenon of the ink due to thermal energy, the ejection becomes extremely stable, and the generation of satellite dots does not occur. There are features. However, in this case, the thermal physical property value (for example, specific heat, thermal expansion coefficient, thermal conductivity, etc.) may be adjusted.

Furthermore, the ink of the present invention is intended to solve the problems of ink bleeding and drying and permeation of the recorded matter when recorded on plain paper and the like, and at the same time, to improve the matching with the ink jet head. As a physical property of itself, the surface tension at 25 ° C. is 30 to 68 dyne / c.
m and the viscosity are desirably adjusted to 15 cP or less, preferably 10 cP or less, more preferably 5 cP or less. Therefore, in order to adjust the ink to the above physical properties and to solve the problem in plain paper, the amount of water contained in the ink of the present invention should be 50% by weight or more, more preferably 60% by weight.
It is preferable that the above is performed.

The ink of the present invention is particularly suitably used for an ink jet recording method in which recording is performed by discharging droplets by the action of thermal energy, but it goes without saying that it can also be used for general writing instruments. As a method and apparatus suitable for performing recording using the ink of the present invention, a method and apparatus for applying thermal energy corresponding to a recording signal to ink in a chamber of a recording head and generating droplets by the thermal energy are known. No.

FIGS. 1, 2 and 3 show examples of the structure of a head which is a main part of the apparatus. The head 13 is formed by bonding a glass, ceramic or plastic plate having a groove 14 through which ink passes, and a heating head 15 (a head is shown in the figure, but is not limited to this) used for thermal recording. Is obtained. The heating head 15 includes a protective film 16 made of silicon oxide or the like, and an aluminum electrode 17.
-1, 17-2, heat generating resistor layer 18 made of nichrome or the like, heat storage layer 19, substrate 20 having good heat dissipation such as alumina
Is made up of The ink 21 reaches a discharge orifice (fine hole) 22 and forms a meniscus 23 by the pressure P.

When an electric signal is applied to the electrodes 17-1 and 17-2, the area of the heating head 15 indicated by n rapidly generates heat, and bubbles are generated in the ink 21 in contact with the area.
The meniscus 23 is protruded by the pressure, the ink 21 is ejected, becomes a recording droplet 24 from the orifice 22, and flies toward the recording material 25. FIG. 3 shows an external view of a multi-head in which many heads shown in FIG. 1 are arranged. The multi-head is manufactured by closely contacting a glass plate 27 having a multi-groove 26 and a heating head 28 similar to that described with reference to FIG. FIG. 1 is a cross-sectional view of the head 13 along the ink flow path, and FIG. 2 is a cross-sectional view taken along line AB in FIG.

FIG. 4 shows an example of an ink jet recording apparatus incorporating such a head. In FIG. 4, reference numeral 61 denotes a blade as a wiping member, one end of which is held by a blade holding member to become a fixed end, and forms a cantilever. The blade 61 is disposed at a position adjacent to a recording area of the recording head, and in this example, is held in a form protruding into the movement path of the recording head. Reference numeral 62 denotes a cap, which is disposed at a home position adjacent to the blade 61, and has a configuration in which the cap moves in a direction perpendicular to the direction in which the print head moves and comes into contact with the ejection port surface to perform capping. Further, 63 is an ink absorber provided adjacent to the blade 61, similar to the blade 61.
It is held in a form protruding into the movement path of the recording head.
The blade 61, the cap 62, and the absorber 63 constitute an ejection recovery unit 64, and the blade 61 and the absorber 6
3 removes moisture, dust and the like from the ink ejection port surface.

Reference numeral 65 denotes a recording head which has discharge energy generating means and discharges ink on a recording material facing a discharge port surface provided with discharge ports to perform recording, and 66 denotes a recording head on which the recording head 65 is mounted. A carriage for performing the movement 65. The carriage 66 is slidably engaged with the guide shaft 67, and a part of the carriage 66 is connected to a belt 69 driven by a motor 68 (not shown). As a result, the carriage 66 can move along the guide shaft 67, and the recording head 65 can move the recording area and the adjacent area. Reference numeral 51 denotes a paper feed unit for inserting a recording material, and 52 denotes a paper feed roller driven by a motor (not shown). With such a configuration, the recording material is fed to a position facing the ejection port surface of the recording head, and is discharged to a discharge section provided with a discharge roller 53 as recording proceeds.

In the above configuration, when the recording head 65 returns to the home position at the end of recording or the like, the cap 62 of the head recovery unit 64 is retracted from the moving path of the recording head 65, but the blade 61 protrudes into the moving path. I have. As a result, the ejection port surface of the recording head 65 is wiped. When capping is performed with the cap 62 in contact with the ejection surface of the recording head 65, the cap 62 moves so as to protrude into the movement path of the recording head. Recording head 6
When 5 moves from the home position to the recording start position, the cap 62 and the blade 61 are at the same position as the position at the time of wiping described above. As a result, the ejection port surface of the recording head 65 is also wiped during this movement. The movement of the recording head to the home position described above
Not only at the end of recording and at the time of ejection recovery, but also at a predetermined interval, the recording head moves to a home position adjacent to the recording area while moving the recording area for recording, and the wiping is performed along with this movement. .

FIG. 5 is a diagram showing an example of an ink cartridge containing ink supplied to the head via an ink supply member, for example, a tube. Here, reference numeral 40 denotes an ink storage portion that stores the supply ink, for example, an ink bag, and a rubber stopper 42 is provided at the tip thereof. By inserting a needle (not shown) into the stopper 42, the ink in the ink bag 40 can be supplied to the head. 44
Is an ink absorber for receiving waste ink. It is preferable for the present invention that the ink container has a surface in contact with the ink made of polyolefin, particularly polyethylene. The ink jet recording apparatus used in the present invention is not limited to the one in which the head and the ink cartridge are separated as described above, but may be suitably used in an integrated one as shown in FIG.

In FIG. 6, reference numeral 70 denotes a recording unit, in which an ink container containing ink, for example, an ink absorber is stored, and the ink in the ink absorber has a plurality of orifices. Head part 71
Are ejected as ink droplets from the ink. As the material of the ink absorber, it is preferable for the present invention to use polyurethane. Reference numeral 72 denotes an atmosphere communication port for communicating the inside of the cartridge with the atmosphere. The recording unit 70 is used in place of the recording head shown in FIG. 4, and is detachable from the carriage 66.

[0028]

Next, the present invention will be described more specifically with reference to examples and comparative examples. In the following description, parts and% are based on weight unless otherwise specified. Examples 1 to 7 The inks of the present invention having the compositions shown in Table 1 were prepared using the exemplified compounds.

(Table 1) Example 1 25 parts of ethylene glycol 10 parts of N-methyl-2-pyrrolidone 60 parts of pure water Compound 2 (M = Na) 5 parts Example 2 diethylene glycol 15 parts Pure water 82 parts Compound 3 (M = NH ₄ ) 3 parts Example 3 15 parts of diethylene glycol 5 parts of ethylene glycol monomethyl ether 76 parts of pure water Compound 4 (M = Na) 4 parts Example 4 Ethylene glycol 10 parts N-methyl-2-pyrrolidone 5 parts Pure water 82 parts Compound 3 (M = Li) 3 parts Example 5 glycerin 12 parts Ethylene glycol 8 parts Pure water 75 parts Compound (4) (M = K) 5 parts Example 6 18 parts of diethylene glycol 2-pyrrolidone 5 parts 71 parts of pure water 6 parts (M = NH ₄ ) 4 parts Example 7 glycerin 10 parts Ethylene glycol monoethyl ether 5 parts Pure water 81 parts 7 parts (M = NH (CH ₃ ) ₃ ) 4 parts

Next, a recording apparatus having an on-demand type multi-head (Canon) for performing recording by applying thermal energy to the ink in the recording head to generate droplets using the inks of the above-described embodiments 1 to 7 is described. Solid print by Bubble Jet Printer BJ-130).
A print piece having a size of 20 mm was prepared. As paper, recommended paper for Canon NP-6150, Neusiedler paper, and prober bond paper were used. The optical density of the printed material for Example 1-7, was in the range of 1.25 to 1.50.

Further, the inks of Examples 1 to 7 were evaluated for the following characteristics of T _{1 to} T ₅ . (T ₁ ) Long-term storage of ink: Each ink was sealed in a glass container and stored at 0 ° C. and 40 ° C. for 6 months.

(T ₂ ) Ejection stability: Continuous ejection was performed for 24 hours using the above recording apparatus.

(T ₃ ) Discharge response: Intermittent discharge every 2 seconds and discharge after leaving for one month were examined using the above-mentioned recording apparatus.

(T ₄ ) Lightfastness: Printed piece of prober bond paper (10 × 20 m)
m) was irradiated with light for 100 hours, and the rate of decrease in optical density was measured. ：: Decrease rate of optical density is 9% or less ○: Decrease rate of optical density is in the range of 10% to 14% Δ: Decrease rate of optical density is in the range of 15% to 25% ×: Decrease rate of optical density Is more than 26%

(T ₅ ) Water resistance: A printed piece of a printed Neusiedler paper (10 × 20 mm)
Was immersed in water at 20 ° C. for 3 hours, and the rate of decrease in optical density was measured. ：: Decrease rate of optical density is 9% or less ○: Decrease rate of optical density is in the range of 10% to 14% Δ: Decrease rate of optical density is in the range of 15% to 25% ×: Decrease rate of optical density Is 26% or more The evaluation results of the above T _{1 to} T ₅ are shown in Tables 6 and 7 below.

Comparative Examples 1 to 4 On the other hand, for comparison, inks having the composition shown in Table 2 below were prepared by using the compounds shown in Table 3 below in which the number of sulfonic acid groups was larger than the number of amino groups in place of the compounds used in the present invention. in the same manner as described above was evaluated for the above T ₁ ~T _5. The evaluation results are shown in Table 6 below.

(Table 2) Comparative Example 1 Ethylene glycol 25 parts N-methyl-2-pyrrolidone 10 parts Pure water 60 parts Compound 3 (M = Na) 3 parts Comparative Example 2 Diethylene glycol 15 parts Pure water 82 parts Compound No. 2 (M = NH ₄ ) 3 parts Comparative Example 3 Ethylene glycol 20 parts Pure water 76 parts No. 3 Compound {M = NH (C ₂ H ₄ OH) ₃ } 4 parts Comparative Example 4 Triethylene glycol 25 parts Ethylene glycol monomethyl ether 15 parts Pure water 55 parts Compound (4) (M = Na) 5 parts

[0038]

Comparative Examples 5 to 7 On the other hand, for comparison, inks having the compositions shown in Table 4 below were prepared by using the compounds shown in Table 5 below in which the number of sulfonic acid groups was larger than the number of carboxyl groups in place of the compounds used in the present invention. Evaluations on T _{1 to} T ₅ were performed in the same manner as described above. The evaluation results are shown in Table 6 below.

(Table 4) Comparative Example 5 15 parts of glycerin 10 parts of 2-pyrrolidone 71 parts of pure water Compound No. 1 (M = Na) 4 parts Comparative Example 6 Triethylene glycol 15 parts Pure water 80 parts Compound 5 (M = NH ₄ ) 5 parts Comparative Example 7 Ethylene glycol 25 parts Ethylene glycol monomethyl ether 10 parts Pure water 60 parts 5 parts of the compound of No. 3 (M = Li)

[0041]

[0042]

[0043]

As is apparent from the above description, according to the present invention, by selecting a compound having a specific structure as a coloring material of an ink, a printed matter excellent in light fastness and water fastness especially on plain paper can be obtained. Is provided.

[0045]

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a head section of an ink jet recording apparatus.

FIG. 2 is a cross-sectional view of a head section of the inkjet recording apparatus.

FIG. 3 is an external perspective view of a head obtained by multiplying the head shown in FIG.

FIG. 4 is a perspective view illustrating an example of an inkjet recording apparatus.

FIG. 5 is a longitudinal sectional view of the ink cartridge.

FIG. 6 is a perspective view of a recording unit.

[Explanation of symbols]

 61: Wiping member 62: Cap 63: Ink absorber 64: Discharge recovery unit 65: Recording head 66: Carriage

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-54-144067 (JP, A) JP-A-61-285275 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09D 11/00-11/20 CA (STN) REGISTRY (STN)

Claims (11)

(57) [Claims] 1. An ink containing at least water, a water-soluble organic solvent and a dye, wherein the dye is represented by the following general formula (1):
Wherein the number of sulfonic acid groups and the number of amino groups in one molecule are each 2 or more, and the sulfonic acid group number is smaller than the number of amino groups. (However, Q ₁ in the formula (1) represents a phenyl group, a pyridyl group or a naphthyl group substituted with a group selected from NH ₂ and SO ₃ M, and Q ₂ is CH ₃ , OCH ₃ , NHCOCH ₃ And a p-phenylene group or 1,4 substituted with a group selected from SO ₃ M
Represents a naphthylene group; Q ₃ represents an unsubstituted or SO ₃ M-substituted diaminopyridyl group or a COOM or SO ₃ M-substituted diaminophenyl group; M represents an alkali metal, ammonium or organic Represents ammonium, and n represents 0 or 1. ) 2. The dye of the following No. 1 to No. The ink according to claim 1, which is a compound represented by the formula (7). 3. An ink jet recording method in which ink droplets are ejected from an orifice according to a recording signal to perform recording, wherein the ink is the ink according to claim 1. 4. The ink jet recording method according to claim 3, wherein the ink is ejected by applying thermal energy to the ink. 5. A recording unit comprising an ink containing section containing ink and a head section for ejecting the ink as ink droplets, wherein the ink is the ink according to claim 1. unit. 6. The recording unit according to claim 5, wherein the head section is a head for ejecting ink droplets by applying thermal energy to the ink. 7. An ink cartridge provided with an ink containing section containing ink, wherein the ink is the ink according to claim 1. 8. An ink jet recording apparatus comprising: a recording unit having an ink storage section for storing ink and a head section for discharging the ink as ink droplets, wherein the ink is the ink according to claim 1. An ink jet recording apparatus comprising: 9. The ink jet recording apparatus according to claim 8, wherein the head section is a head that applies thermal energy to the ink to eject ink droplets. 10. A recording head for discharging ink droplets,
2. An ink jet recording apparatus, comprising: an ink cartridge having an ink containing section containing ink; and an ink supply section for supplying ink from the ink cartridge to a recording head, wherein the ink is the ink according to claim 1. Characteristic inkjet recording device. 11. The ink jet recording apparatus according to claim 10, wherein the recording head is a head that applies thermal energy to the ink to eject ink droplets.