JP3060320B2 - Ink, inkjet recording method and apparatus using the same - 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 same, and an apparatus using the ink. The present invention relates to not only coated paper specially adjusted for ink-jet but also other copy paper. High-definition, high-quality recording is possible even for uncoated paper commonly used in offices and homes, such as report paper, bond paper, and continuous slip paper, so-called plain paper, and uses thermal energy. The present invention relates to an ink, an ink jet recording method, a recording unit, an ink jet recording apparatus, and an ink cartridge suitable for the present invention.

[0002]

2. Description of the Related Art Ink-jet inks of various compositions have hitherto been reported. In particular, in recent years, in order to perform good recording on plain paper commonly used in offices such as copy paper, report paper, notebooks, stationery, etc., detailed research and development has been carried out from various aspects such as composition and physical properties. Have been.

[0003] In the ink jet recording method, various methods have been proposed. A method in which charged droplets are continuously generated and a part of the droplets are used for recording. A method in which a signal is applied and recording is performed by generating droplets of the recording liquid in accordance with the signal, or thermal energy corresponding to the recording signal is applied to the recording liquid in the room of the recording head, and a droplet is generated by the energy. For example, there is a method of performing recording.

In particular, the type described in Japanese Patent Application Laid-Open No. 54-59936, in which the ink is ejected by the bubbling phenomenon of the ink by thermal energy, makes it easy to achieve high integration and high density of the nozzles. It is a method that collects. However, stricter conditions are required for the ink used in order to utilize the phenomenon of foaming which is not available in other systems.

The preferred conditions of the ink used in this method are listed below. (1) The responsiveness of foaming to thermal energy is good, and droplets are always stably ejected from fine ejection openings. , No clogging. (2) Stable ejection can be obtained immediately after resuming printing even if the cap is left uncapped during printing pause. That is, the ink in the vicinity of the discharge port is not easily dried and does not cause clogging. (3) A high-quality image without irregular or irregular bleeding can be obtained, especially on plain paper. (4) Fast fixability (print drying property) on plain paper,
No stain when rubbing printed matter. (5) The storage stability is good, and the ink performance is maintained for a long time. (6) Excellent safety such as toxicity and flammability. And the like.

In response to these demands, the conventional ink formulation is not particularly limited to the thermal energy type in the ejection method. For example, in general, the ink contains glycol or the like for the purpose of preventing drying and clogging. When recording on plain paper with a high degree of size using such an ink, which contains a high-boiling organic solvent, the ink hardly penetrates into the paper and the recording part has poor drying properties. There were problems such as ink sticking to the hand when touched by hand, and rubbing and smearing of characters.

Therefore, in order to enhance the permeability of the ink into the paper, Japanese Patent Application Laid-Open No. 55-29546 proposes a method of adding a large amount of a surfactant to the ink.
In this case, very much bleeding occurs depending on the paper, or when the ink is filled in the ink jet head, depending on the structure of the head, the ink recedes from the orifice surface and the ink is not discharged. Troubles such as the entire surface being wet and no ink being ejected were observed.

Japanese Patent Application Laid-Open No. 56-57862 also proposes a method for making the pH of the ink strongly alkaline. However, this method is dangerous when the ink is touched by hand.
In addition, there is a drawback that paper using a certain type of sizing agent, such as neutral paper, may bleed and dryness may not be good.

Although various improvements have been attempted in addition to the above, all of the above-mentioned problems of bleeding, drying, and clogging can be sufficiently achieved even if there is no limitation to use the thermal energy system. At present, there is no known ink that solves this problem.In addition, it is important to design an ink that can further respond to the phenomenon peculiar to the thermal energy method of firing. It is a difficult task.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide an uncoated paper generally used in offices, such as copy paper, report paper, notebooks, and stationery, which has good foaming response to heat energy. It is an object of the present invention to provide an ink and an ink jet recording method which solve the bleeding of the ink and the slow drying property of the recorded matter when recording on so-called plain paper, and to provide a device using such an ink.

Another object of the present invention is to provide an ink which is highly safe for use in offices and homes.

Still another object of the present invention is to provide an ink which hardly causes clogging of a nozzle of an ink jet recording head and which has excellent reliability, and a device using such an ink.

[0013]

The above object is achieved by the present invention described below.

That is, the present invention relates to an ink containing a recording agent and a liquid medium for dissolving or dispersing the same.
An ink containing 1,2,3-propanetriol.

According to the present invention, there is provided an ink jet recording method for discharging ink droplets from an orifice in accordance with a recording signal to perform recording on a recording material, wherein the ink is used.

According to the present invention, there is provided a recording unit including an ink containing section containing ink and a head section for discharging the ink as ink droplets, wherein the above ink is used as the ink. .

According to the present invention, there is provided an ink cartridge provided with an ink storage section for storing ink, wherein the above ink is used as the ink.

The present invention is characterized in that the ink described above is used as an ink in an ink jet recording apparatus provided with an ink container containing an ink and a recording unit having a head for discharging the ink as ink droplets. This is an inkjet recording apparatus that performs the following.

According to the present invention, there is provided an ink jet recording apparatus having a recording head for discharging ink droplets, an ink cartridge having an ink storage section for storing ink, and an ink supply section for supplying ink from the ink cartridge to the recording head. An ink jet recording apparatus characterized in that the above ink is used as the ink in the apparatus.

(Preferred Aspects of the Present Invention) The present inventors are particularly suitable for recording in which ink is ejected by the bubbling phenomenon of ink due to thermal energy, and improve ink bleeding, drying properties and permeability on paper, Furthermore, as a result of intensive studies on a highly reliable ink composition that is unlikely to cause clogging in nozzles of an ink jet recording head, the ink containing 2-methyl-1,2,3-propanetriol together with water as a liquid medium has bleeding and permeability. In this regard, the present invention has been found to have a good balance with respect to the above, and has found that the clogging prevention property is particularly good, and has reached the present invention.

According to the findings of the present inventors, glycols such as polyethylene glycol, glycerin and the like have been used as a clogging preventive agent for inks in the past. It is a particularly preferable anti-clogging agent because it can prevent the ink from bleeding on the paper surface. However, since the wettability to the sizing agent present in the paper is poor, some papers have a drawback that the drying property and the permeability of the ink on the paper surface are extremely poor.

On the other hand, the 2-methyl-
1,2,3, -propanetriol has the same effect of preventing clogging as glycerin, and has a very good balance between ink bleeding and permeability. The reason is that
The compound has a low vapor pressure and has three hydroxyl groups like glycerin, so that it is excellent in dissolving or dispersing the dye, and as a result, it is considered that an effect of preventing clogging is obtained. Further, it is considered that since the carbon number is larger than that of glycerin, the molecule has a hydrophilic portion and a hydrophobic portion in the molecule, so that the wettability to the sizing agent is good, and as a result, the permeability of the ink on the paper surface is remarkably improved.

On the other hand, the responsiveness to foaming is such that the content of the compound in the ink is 0.1 to 30% by weight and water is 50%.
Particularly good when the content is from 95 to 95% by weight. This is presumably because the physical properties of the ink mixed in the above ratio and the wettability to each member inside the nozzle are optimal for a recording method in which the ink is ejected by a foaming phenomenon of the ink due to thermal energy.

Next, each component of the ink of the present invention will be described.

As used in the present invention and mainly characterizing the present invention, the addition of 2-methyl-1,2,3-propanetriol to the ink is used alone or in a mixed system. It depends on the liquid medium components of the
The proportion occupies about 0.1 to 30% by weight, preferably 0.1 to 25% by weight, more preferably 1 to 20% by weight.

When the content is less than 0.1% by weight,
No clogging prevention effect is observed. In addition, this content is 30
If it exceeds% by weight, problems occur in terms of permeability and bleeding.

The pigments constituting the ink of the present invention include:
Direct dyes, acid dyes, food dyes, basic dyes, reactive dyes, disperse dyes, architectural dyes, soluble architectural dyes, reactive disperse dyes, oil-based dyes, and various pigments can be mentioned. Particularly preferred.

The content of these dyes is determined depending on the type of the liquid medium component, the characteristics required for the ink, and the like, but is generally about 0.2 to 2% by weight in the total amount of the ink.
0%, preferably 0.5 to 10%, more preferably 1%
It accounts for up to 5%.

The proportion of water in the ink which is an essential component of the present invention is 50 to 95% by weight, preferably 55 to 95% by weight, more preferably 60 to 95% by weight. When the amount of water is less than 50% by weight, the amount of the organic solvent is large, and the paper curls or the print quality on plain paper or the like is significantly deteriorated. When the amount of water exceeds 95% by weight, the discharge stability from the nozzle orifice may be significantly deteriorated.

The essential components of the ink of the present invention are as described above, but other common organic solvents used in conventionally known inks can also be used in combination. Examples of the organic solvent include methyl alcohol, ethyl alcohol and n-fluoro. Pill alcohol, isopropyl alcohol, n-butyl alcohol,
C1-C5 alkyl alcohols such as sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol and n-pentanol; amides such as dimethylformamide and dimethylacetamide; acetone;
Ketone or keto alcohols such as diacetone alcohol; ethers such as tetrahydrofuran and dioxane;
Oxyethylene or oxypropylene addition polymers such as diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol and polypropylene glycol; ethylene glycol, propylene glycol, trimethylene glycol, butylene glycol, 1, 2 Alkylene glycols having an alkylene group containing from 2 to 6 carbon atoms, such as, 6-hexanetriol and hexylene glycol; thiodiglycol; glycerin; ethylene glycol monomethyl (or ethyl) ether, diethylene glycol monomethyl (or ethyl) ether; Lower alkyl ethers of polyhydric alcohols such as triethylene glycol monomethyl (or ethyl) ether; Lower dialkyl ethers of polyhydric alcohols such as lenglycol dimethyl (or ethyl) ether and tetraethylene glycol dimethyl (or ethyl) ether; sulfolane, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone And the like.

The content of the water-soluble organic solvent is generally in the range of 1 to 49%, preferably 2 to 30% by weight based on the total weight of the ink.

When the above-mentioned medium is used together, it can be used alone or as a mixture. The most preferable liquid medium composition is at least one water-soluble high-boiling organic solvent, for example, a polyvalent solvent such as diethylene glycol, triethylene glycol and glycerin. It contains alcohol.

Other various dispersants, surfactants, viscosity adjusters, surface tension adjusters, fluorescent brighteners and the like can be added as required.

For example, viscosity modifiers such as polyvinyl alcohol, celluloses and water-soluble resins; various surfactants of cation, anion or nonionic type; surface tension modifiers such as diethanolamine and triethanolamine; pH adjustment by buffer solution Agents, fungicides and the like.

Further, the ink of the present invention solves the bleeding of the ink and the drying and penetrating properties of the recorded matter when it is recorded on plain paper or the like. Tension is 30
It is desirable to adjust the viscosity to 68 dyne / cm and the viscosity to 15 cP or less, preferably 10 cP or less, and more preferably 5 cP or less.

The ink of the present invention is particularly suitably used for an ink jet recording method in which recording is performed by discharging liquid 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, there is provided a method in which thermal energy corresponding to a recording signal is applied to ink in a chamber of a recording head and droplets are generated by the thermal energy. And a device.

FIGS. 1, 2 and 3 show examples of the structure of a head which is a main part of the apparatus.

The head 13 includes a glass, ceramic or plastic plate having a groove 14 through which ink passes, and a heating head 15 used for thermal recording (a head is shown in the figure, but is not limited to this). And obtained by bonding. The heating head 15 includes a protective film 16 made of silicon oxide or the like, and aluminum electrodes 17-1 and 17-.
2, a heat-generating low-antibody layer 18 made of nichrome or the like, a heat storage layer 19, and a substrate 20 having good heat dissipation such as alumina.

The ink 21 has a discharge orifice (fine hole) 2
2, and the meniscus 23 is formed 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, and becomes a recording droplet 24 from the orifice 22.
Fly towards 5.

FIG. 3 is 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 shows the head 13 along the ink flow path.
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 the 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. Reference numeral 63 denotes an ink absorber provided adjacent to the blade 61, which is held in a form protruding into the movement path of the recording head, similarly to the blade 61. The blade 61, the cap 62, and the absorber 63 constitute an ejection recovery unit 64, and the blade 61 and the absorber 63 remove water, 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 recording material ink facing a discharge port surface provided with discharge ports to perform recording, and 66 denotes a recording head on which a recording head 65 is mounted. Is a carriage for performing the movement. 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, 5
Reference numeral 2 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.

When the recording head 65 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 above-described movement of the print head to the home position is performed not only at the end of printing or at the time of ejection recovery, but also at a predetermined interval between the printing head and the home position adjacent to the printing area while the printing head moves through the printing area for printing. Position, and the wiping is performed along with the movement.

FIG. 5 shows an ink supply member, for example,
FIG. 3 is a diagram illustrating an example of an ink cartridge that stores ink supplied via 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 absorber for receiving waste ink.

It is preferable for the present invention that the ink container has a liquid contact surface with the ink formed 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 from each other as described above, but is also suitable for the one in which they are integrated as shown in FIG. Used.

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 recording unit with the atmosphere.

This recording unit 70 is used in place of the recording head shown in FIG.
6 is detachable.

[0057]

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 5 After the following components were mixed and stirred for 5 hours, the pH was adjusted to 7.5 with a 0.1% aqueous solution of sodium hydroxide, and further a membrane filter having a bore size of 0.22 micron. The mixture was filtered under pressure with a trade name (Fluorobore Filter, manufactured by Sumitomo Electric Industries, Ltd.) to obtain Inks A to E of the present invention.

Next, using the obtained inks A to E, as an ink jet recording apparatus, an ink jet printer BJ130 (trade name: manufactured by Canon Inc.) using a heating element as an ink ejection energy source was used. Recording on copy paper and bond paper, and fixability and bleeding rate of the recorded matter obtained, clogging during reprinting after temporary suspension of printing, clogging during reprinting after long-term suspension of printing The frequency response was evaluated. The results are shown in Table 1. The evaluation was usually performed at 25 ° C. and 60% RH.

Ink A C.I. I. Direct Yellow 86 2 parts 2-Methyl-1,2,3-propanetriol 17 parts Water 81 parts

Ink B C.I. I. Acid Red 35 2 parts 2-Methyl-1,2,3-propanetriol 7 parts Glycerin 5 parts Water 86 parts

Ink C C.I. I. Food black 2 3 parts Triethylene glycol 6 parts 2-methyl-1,2,3-propanetriol 6 parts Ethanol 3 parts Water 82 parts

Ink D C.I. I. Direct Blue 199 2.5 parts Diethylene glycol 4 parts 2-Methyl-1,2,3-propanetriol 10 parts n-butanol 2 parts Water 81.5 parts

Ink E C.I. I. Direct Black 154 2 parts 2-Methyl-1,2,3-propanetriol 8 parts Thiodiglycol 3 parts Diethylene glycol 3 parts Ethanol 2 parts Water 83 parts

Comparative Examples 1 to 5 In the same manner as in Examples 1 to 5, all the following components were treated to obtain Inks F to J of Comparative Examples 1 to 5, and various evaluations were performed in the same manner as in the Examples. Was. The result is first displayed.

Ink F C.I. I. Direct Yellow 86 2 parts Glycerin 17 parts Water 81 parts

Ink G C.I. I. Food Black 2 3 parts Triethylene glycol 12 parts Ethanol 3 parts Water 82 parts

Ink H C.I. I. Direct Blue 199 2.5 parts Diethylene glycol 14 parts n-butanol 2 parts Water 81.5 parts

Ink I C.I. I. Direct Black 154 2 parts PEG300 14 parts Nonionic surfactant (trade name: Nitsusan Nonion P22
3 Nippon Oil & Fats Co., Ltd.) 0.5 parts Water 83.5 parts

Ink J C. I Food Black 2 3 parts Ethylene glycol 15 parts Isopropyl alcohol 2 parts Water 80 parts

[0071]

[Table 1]

(1 ^* ) Evaluation of Fixability After printing for 10 seconds on commercial copy paper and bond paper, 30
Two seconds later, the printed portion was rubbed with filter paper (trade name: No. 5C, manufactured by Toyo Roshi Kaisha, Ltd.). ◎: No blurring in 10 seconds ○: Small blurring in 10 seconds △: Small blurring in 30 seconds ×: Large blurring in 30 seconds

(2 ^* ) Dot Shape Regarding the occurrence rate of bleeding, after printing 300 dots on a commercially available copy paper or bond paper with a printer so as not to be continuous, the bleeding was observed with a microscope after being left for one hour or more. The number of dots formed was counted and expressed in%. ：: 10% or less △: 11 to 30% ×: 31% or more

(3 ^* ) Clogging at the time of reprinting after the printing is temporarily stopped For clogging at the time of reprinting after the printing is temporarily stopped, the printer is filled with the predetermined ink and alphanumeric characters are continuously printed for 10 minutes. After printing, the printing was stopped, left for 10 minutes without a cap or the like, and then alphanumeric characters were printed again to determine the presence or absence of defective portions such as blurred or missing characters. ：: No defective portion from the first character. Δ: Part of the first character is blurred or chipped. X: The first character cannot be printed at all.

(4 ^* ) Recoverability of clogging at the time of reprinting after printing has been stopped for a long period of time After printing the printer with predetermined ink and printing alphanumeric characters continuously for 10 minutes, stop printing, and do not cap the printer After standing for 7 days in the state, the nozzle clogging recovery operation was performed, and it was determined how many times the number of operations allowed normal printing without character blurring, chipping, etc. (60 ° C., 10 ± 5% R).
H). ： １: Normal printing is possible with 1 to 5 recovery operations. Δ: Normal printing is possible with 6 to 10 recovery operations. X: Normal printing is possible by 11 or more recovery operations.

(5 ^* ) Evaluation of Frequency Responsivity The printed state of the obtained printed matter, that is, a state of blurring or white spots, and a state of poor landing point such as splash or twist were visually observed and evaluated. A: The ink followability to frequency is good, and no blurring, white spots, or defective landing points are observed in both solid printing and character printing. …: Ink followability to frequency is almost good,
No blurring, white spots, or landing point defects are found in character printing, but slight blurring is seen in solid printing. Δ: No blurred spots are seen in character printing, but some impact point failures are seen.

Further, in solid printing, blurring and white spots are observed about 1/3 of the entire solid. C: Many blurs and white spots were observed in solid printing, and many blurs and landing point defects were observed in character printing.

[0078]

As described above, according to the ink of the present invention, the responsiveness of foaming to heat energy is good.
It is possible to record high-quality and high-permeability recording without bleeding even on ordinary plain paper generally used in offices such as copy paper, report paper, notebooks, and stationery.

Further, according to the present invention, it is possible to obtain an ink which is highly safe for use in offices and homes.

Further, according to the present invention, it is possible to perform highly reliable recording without causing clogging of the nozzles of the ink jet head.

By using the ink of the present invention, a highly reliable device can be provided.

[Brief description of the drawings]

FIG. 1 is a longitudinal 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. 1;

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

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

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

[Explanation of symbols]

 13 Head 15 Heating Head 21 Ink 25 Recording Material 28 Heating Head 40 Ink Bag 44 Ink Absorber 45 Ink Cartridge 61 Wiping Member 65 Recording Head 66 Carriage 70 Recording Unit 71 Head Section 72 Atmospheric Communication Hole

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-211471 (JP, A) JP-A-59-49276 (JP, A) JP-A-1-282273 (JP, A) JP-A 54-49 59936 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C09D 11/00-11/20 CA (STN) REGISTRY (STN)

Claims (20)

(57) [Claims] 1. An ink containing a recording agent and a liquid medium for dissolving or dispersing the recording agent, wherein the ink contains 2-methyl-1,2,3-propanetriol. 2. The ink according to claim 1, wherein the content of the triol is in the range of 0.1 to 30% of the total weight of the ink. 3. The ink according to claim 1, wherein the liquid medium contains water. 4. The content of water is 50 to 95 of the total weight of the ink.
The ink of claim 3 in the range of%. 5. The ink according to claim 1, comprising a water-soluble organic solvent as a liquid medium. 6. The ink according to claim 5, wherein the content of the water-soluble organic solvent is in the range of 1 to 49% of the total weight of the ink. 7. An ink jet recording method in which an ink droplet is ejected from an orifice in accordance with a recording signal to perform recording on a recording material, wherein the ink is the ink according to any one of claims 1 to 6. An inkjet recording method, comprising: 8. The recording material is an uncoated paper.
3. The inkjet recording method according to item 1. 9. The ink jet recording method according to claim 7, wherein the ink is ejected by applying thermal energy to the ink. 10. A recording unit comprising: an ink storage section for storing ink; and a head section for discharging the ink as ink droplets, wherein the ink is defined by any one of claims 1 to 6.
A recording unit, which is the ink according to any one of the above. 11. The recording unit according to claim 10, wherein the ink container is formed of polyurethane. 12. The head unit includes a head for ejecting ink droplets by applying thermal energy to ink.
The recording unit according to 0. 13. An ink cartridge comprising an ink container portion containing an ink, wherein the ink according to claim 1
7. An ink cartridge comprising the ink according to any one of claims 6 to 6 . 14. The ink cartridge according to claim 13, wherein the ink container has a liquid contact surface formed of polyolefin. 15. 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 any one of claims 1 to 6. An ink jet recording apparatus comprising the ink described in the above. 16. The ink jet recording apparatus according to claim 15, wherein the ink containing section is made of polyurethane. 17. The ink jet printer according to claim 1, wherein the head unit includes a head for ejecting ink droplets by applying thermal energy to the ink.
6. The ink jet recording apparatus according to 5. 18. A recording head for discharging ink droplets,
7. 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 any one of claims 1 to 6. An ink jet recording apparatus characterized by being the ink described in>. 19. The ink jet recording apparatus according to claim 18, wherein the ink containing section has a liquid contact surface formed of polyolefin. 20. The ink jet recording apparatus according to claim 18, wherein the recording head is a head that applies thermal energy to the ink to eject ink droplets.