JPH04339875A - Ink, ink jet recording by using it, and machinery using the ink - Google Patents

Abstract

PURPOSE:To obtain an ink improved in the prevention of solidification and clogging, and recording properties by dissolving or dispersing a recording agent, an organic amine salt of a dicarboxylic acid, and an alkylamine in a liquid medium. CONSTITUTION:0.1-15wt.% recording agent, 0.1-10.0wt.% organic amine salt of a dicarboxylic acid, and 0.1-10.0wt.% alkylamine are dispersed or dissolved in a liquid medium consisting of 30-95wt.% water and 1-40wt.% water-soluble organic solvent to give an ink 21. The ink 21 is put between a plate 13 with a groove 14 for passing the ink and a heat generating head 15 consisting of a protective film 16, Al electrodes 17-1 and 17-2, a heat generating resistor layer 18, a heat storage layer 19, and a base plate 20. An electric signal is applied to the electrodes 17-1 and 17-2 to produce air bubbles near the region n of the head 15 so that the pressure causes a meniscus 23 to project and the ink 21 from an orifice 22 is deposited as recording droplets 24 on a recording medium 25.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to an ink, an inkjet recording method using the same, and equipment using such an ink, and more particularly, the present invention relates to an ink that has excellent solidification prevention properties and clogging prevention properties, and is suitable for use in general offices, etc. Ink that can perform good recording with high density and high image quality on uncoated paper such as high-quality paper, acid-free paper, bond paper, recycled paper, so-called plain paper, and other recording materials used in , relates to an inkjet recording method using the ink, and an apparatus using the ink.

0002

[Prior art] Writing instruments (fountain pens, felt-tip pens,
A wide variety of compositions have been reported for inks for water-based ballpoint pens and inkjet inks. In recent years, ink composition and physical properties have been developed to enable good recording even on plain papers commonly used in offices, such as copy paper, report paper, notebooks, stationery, bond paper, and continuous slip paper. Detailed research and development is being carried out from various aspects such as: For example, ink generally contains high boiling point organic solvents such as glycol to prevent drying and clogging, but when such ink is used to record on plain paper with a high degree of size. Because it is difficult for the ink to penetrate inside the paper and the drying properties of the recorded area are poor, there are problems with fixation, such as ink getting on your hands when you touch the recorded matter, and letters rubbing and staining. Ta.

On the other hand, in order to improve the permeability of the ink into the inside of the paper, Japanese Patent Laid-Open No. 55-29546 proposes a method of adding a large amount of surfactant to the ink. However, in this case, depending on the type of paper, there may be a lot of bleeding, or when filling a writing instrument, the ink may drip from the tip of the pen, or when filling an inkjet head, the head may Depending on the structural conditions, there were problems such as ink retreating from the orifice surface and no ejection, or conversely, the entire orifice surface getting wet and ink not ejecting. Furthermore, JP-A-56-5786
Publication No. 2 proposes a method of making the pH of the ink strongly alkaline, but in this case, it is dangerous if the ink is touched with hands, and it is also dangerous to use paper that uses a certain kind of sizing agent, for example, Neutral paper and the like have drawbacks such as bleeding and drying properties which may not be good. Furthermore, JP-A-54-1
04933 and Japanese Patent Publication No. 62-14189 disclose a method of adding N,N-bis(polyoxyethylene (or propylene))-P-toluenesulfonic acid amide, etc. to ink. Although this method is effective in improving the solubility of dyes, in order to sufficiently prevent clogging, it is necessary to use a considerable amount of organic solvents such as polyhydric alcohols. There is a problem that it does not dry well on the recording material and stains occur even after a long period of time. Therefore, it is necessary to use a surfactant in order to improve the permeability into the paper. As a result, bleeding occurs and the print quality is not sufficient.

[0004] Furthermore, when used in ink jet recording and when ink ejection is interrupted, there is a problem that when water etc. evaporates, the above-mentioned compound retreats from the orifice surface, resulting in poor clogging prevention properties. Furthermore, as described in JP-A-58-183768 and JP-A-1-129081, it has been proposed to add an alkali salt of dicarboxylic acid to the ink in order to improve the lubricity and clogging properties of the ink. has been done. However, this method has the problem that it is difficult to fix the printed matter at high speed and to achieve high print quality, and it is also difficult to obtain a good clogging prevention effect due to the difference in the alkali component that converts the dicarboxylic acid into a salt. For example, if the ink contains a dicarboxylic acid salt produced using a high viscosity compound such as triethanolamine, it becomes difficult to fix printed matter at high speed. Additionally, if the ink contains a dicarboxylic acid salt produced using a low-viscosity compound such as monoethanolamine, when printed on plain paper, it tends to bleed, leading to a decline in print quality and clogging. The prevention effect is also not good.

Furthermore, when ink contains dicarboxylic acid salts produced from inorganic substances such as sodium hydroxide and potassium hydroxide, it is not only difficult to fix printed matter at high speed;
The clogging prevention effect is also not good. Various improvements have been attempted in addition to the above, but to date no ink has been known that satisfactorily solves all of the problems of dryness, print quality, and clogging. is the current situation.

[0006]

[Problems to be Solved by the Invention] Therefore, it is an object of the present invention to prevent ink from solidifying, and to prevent clogging of the printer head even when the pen tip of a writing instrument or printer device is temporarily stopped or stopped for a long time. , Even in the event of clogging, it should be easy to recover from the problem. Non-coated paper such as high-quality paper, acid-free paper, bond paper, recycled paper, etc. used in general offices, etc., so-called plain paper. An object of the present invention is to provide an ink capable of performing good recording with high density and high image quality on and other recording materials, an inkjet recording method using the same, and a device using such an ink.

[0007]

[Means for Solving the Problems] The above object is achieved by the following present invention. That is, the present invention provides an ink comprising a recording agent and a liquid medium for dissolving or dispersing the recording agent, which is characterized by containing an organic amine salt of a dicarboxylic acid and an alkyl amine, an inkjet recording method using the same, and an inkjet recording method using the same. This is a device that uses ink.

[0008]

[Function] The present invention was developed as a result of extensive research into various ink compositions in order to improve ink solidification prevention properties, clogging prevention properties, and high density and high image quality of printed matter. For reasons that are unclear, when an organic amine salt and an alkyl amine are used in combination, when recording on plain paper, the coloring material in the ink becomes difficult to penetrate into the paper, improving the density of the printed matter, and further improving the printing quality. We have discovered that high-quality printing is possible without any disturbance. Furthermore, when an organic amine of a dicarboxylic acid and an alkyl amine are used together in an ink, the ink's anti-solidification and anti-clogging properties are further improved compared to when each is used alone. It has also been found that recovery is very easy even when the volatile components in the ink are completely evaporated. This phenomenon is caused by the synergistic effect of the organic amine salt of dicarboxylic acid and the alkyl amine, which improves dye solubility, suppresses ink evaporation, suppresses viscosity increase during ink concentration, and alleviates coagulation and precipitation of dye when liquid components completely evaporate. It can be assumed that this is to further increase the Due to these effects, the number of clogging recovery operations in the printer system and the amount of ink consumed due to this can be reduced as much as possible, making it possible to use the predetermined amount of ink installed in the printer more efficiently than before. Become.

[0009]

[Preferred Embodiments] Next, the present invention will be explained in more detail by citing preferred embodiments. Specific examples of organic amine salts of dicarboxylic acids used in the present invention include maleic acid, fumaric acid, citraconic acid, itaconic acid, mesaconic acid, 1,1
-cyclobutanedicarboxylic acid, hexahydrophthalic acid,
Camphoric acid, trans-totane-muconic acid, malonic acid, succinic acid, glutaric acid, adipic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylsuccinic acid, 3-methylglutaric acid, pimelic acid, suberic acid, Azelaic acid, sebesic acid, undecanedioic acid, ethylmalonic acid, (1)-
Methyl succinic acid, 3,3-dimethylglutaric anhydride, (
+) Organic amine salts such as 3-methyladipic acid, 1,12-dodecanedicarboxylic acid, hexadecanedioic acid, diglycolic acid, malic acid, tartaric acid, and aspartic acid.

[0010] Also, examples of organic amines include triethanolamine, diethanolamine, monoethanolamine,
Triethylamine, triallylamine, etc. are mentioned, and triethanolamine and triethylamine are particularly good when considering the compatibility with plain paper. The content of the organic amine salt of the dicarboxylic acid is 0.1 to 1% by weight based on the total weight of the ink in terms of fixing properties, print quality, clogging prevention, etc.
A particularly preferred range is 0.0%. Further, examples of the alkylamine to be contained in the ink of the present invention include methylamine, ethylamine, propylamine, dimethylamine,
Examples include diethylamine, trimethylamine, triethylamine, tripropylamine, and the like. The content in the ink is not particularly limited, but when considering the use of plain paper, it is particularly preferably in the range of 0.1 to 10.0% by weight. The coloring material used in the present invention is not particularly limited, and all dyes, pigments, etc. can be used. The content of these coloring materials is not particularly limited, but is generally preferably in the range of 0.1% to 15% by weight based on the total weight of the ink, and more preferably 0.1% to 15% by weight based on the total weight of the ink.
．． It is 1% to 10%.

In addition to the above-mentioned components, the ink of the present invention may optionally contain a water-soluble organic solvent, a surfactant, a pH adjuster, a rust preventive, a preservative, a fungicide, an antioxidant, and an evaporation accelerator. , chelating agents, water-soluble polymers, and other various additives may be added. The liquid medium used in the present invention is preferably a mixture of water and a water-soluble organic solvent. Specific examples of water-soluble organic solvents include amides such as dimethylformamide and dimethylacetamide; ketones such as acetone; ethers such as tetrahydrofuran and dioxane; polyalkylene glycols such as polyethylene glycol and polypropylene glycol; Alkylene glycols in which the alkylene group has 2 to 6 carbon atoms, such as ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol, diethylene glycol; glycerin lower alkyl ethers of polyhydric alcohols such as ethylene glycol monomethyl (or ethyl) ether, diethylene glycol monomethyl (or ethyl) ether, triethylene glycol monomethyl (or ethyl) ether;
N-methyl-2-pyrrolidone, 1,3-dimethyl-2-
Examples include imidazolidinone, triethanolamine, sulfolane, dimethyl sulfoxide and the like.

The content of the water-soluble organic solvent is generally preferably from 1% to 40% by weight, more preferably from 3% to 30%, based on the total weight of the ink. In particular, the amount of wetting agents such as polyhydric alcohols that are commonly used for the purpose of preventing clogging is as follows: By combining an organic amine salt and an alkyl amine, there is no need to use a large amount;
It was found that when the content exceeds 0% by weight, the print fixability and print quality on paper deteriorate. Further, the water content in the ink is more preferably 30% from the viewpoint of the solubility of the coloring material, the viscosity of the ink, sufficient adhesion properties, the density of printed matter, etc.
It is used in a range of 95% by weight.

The ink of the present invention is particularly suitable for application to an inkjet recording method in which ink is ejected by a bubbling phenomenon of ink caused by thermal energy.
It is characterized by extremely stable ejection and no generation of satellite dots. However, in this case, thermal properties (eg, specific heat, coefficient of thermal expansion, thermal conductivity, etc.) may be adjusted. Furthermore, the ink of the present invention solves the problems of ink bleeding when recorded on plain paper, dryness, and permeability of recorded materials, and at the same time improves the physical properties of the ink itself in order to improve matching with inkjet heads. The surface tension at 25℃ is 30-68dyn.
e/cm, and the viscosity is 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-mentioned physical properties and solve the problems with plain paper, the amount of water contained in the ink of the present invention should be 50% by weight or more and 98% by weight or less, preferably 60% by weight or more and 95% by weight or less. It is preferable that the amount is less than % by weight.

The ink of the present invention is particularly suitable for use in an inkjet recording method in which recording is performed by ejecting droplets by the action of thermal energy, but it goes without saying that it can also be used for general writing instruments. A preferred method and apparatus for recording using the ink of the present invention is a method and apparatus that applies thermal energy corresponding to a recording signal to the ink in the chamber of a recording head and generates droplets using the thermal energy. Can be mentioned.

Examples of the configuration of the head, which is the main part of the device, are shown in FIGS. 1, 2, and 3. The head 13 is made by bonding a glass, ceramic, or plastic plate, etc., having grooves 14 through which ink passes, and a heat-generating head 15 (the head is shown in the figure, but is not limited thereto) used for thermal recording. It can be obtained by The heat generating head 15 includes a protective film 16 formed of silicon oxide or the like, and an aluminum electrode 17-.
1, 17-2, heating resistor layer 1 formed of nichrome, etc.
8. It consists of a heat storage layer 19 and a substrate 20 with good heat dissipation properties such as alumina. Ink 21 is a discharge orifice (micropore)
22, and a meniscus 23 is formed due to the pressure P. Now, when an electric signal is applied to the electrodes 17-1 and 17-2, the area indicated by n of the heating head 15 suddenly generates heat, bubbles are generated in the ink 21 in contact with this area, and the pressure causes the meniscus 23 to protrudes, the ink 21 is ejected, becomes a recording droplet 24 from the orifice 22, and the recording material 2
Fly towards 5. FIG. 3 shows an external view of a multi-head in which a large number of heads shown in FIG. 1 are arranged. The multi-head is manufactured by closely adhering a glass plate 27 having multi-grooves 26 and a heating head 28 similar to that explained in FIG. 1. Note that 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 and becomes a fixed end, forming a cantilever shape. The blade 61 is disposed adjacent to the recording area of the recording head, and in this example, is held in a protruding form in the movement path of the recording head. A cap 62 is disposed at a home position adjacent to the blade 61, and is configured to move in a direction perpendicular to the moving direction of the recording head and come into contact with the ejection port surface to perform capping. Furthermore, 63 is an absorber provided adjacent to the blade 61, and like the blade 61, it is held in a protruding form in the moving path of the recording head. The blade 61, the cap 62, and the absorber 63 constitute an ejection recovery section 64, and the blade 61 and the absorber 63 remove moisture, dust, etc. from the ink ejection orifice surface.

Reference numeral 65 includes an ejection energy generating means, and a recording head that performs recording by ejecting ink onto a recording material facing the ejection orifice surface on which the ejection orifices are arranged; and 66, a recording head equipped with the recording head 65; This is a carriage for moving 65. The carriage 66 is slidably engaged with a guide shaft 67, and a portion of the carriage 66 is connected to a belt 69 (not shown) driven by a motor 68. This allows the carriage 66 to move along the guide shaft 67, allowing the recording head 65 to move the recording area and its adjacent area. Reference numeral 51 is a paper feeder for inserting recording material, and 52 is a paper feed roller driven by a motor (not shown). With these configurations, the recording material is fed to a position facing the ejection opening surface of the recording head, and as recording progresses, the recording material is discharged to a paper discharge section provided with a paper discharge roller 53.

In the above configuration, when the recording head 65 returns to the home position after recording is completed, the cap 62 of the head recovery section 64 is retracted from the moving path of the recording head 65, but the blade 61 protrudes into the moving path. There is. As a result, the ejection port surface of the recording head 65 is wiped. Note that when the cap 62 contacts the ejection surface of the recording head 65 to perform capping, the cap 62 moves so as to protrude into the movement path of the recording head. Recording head 65
When moves from the home position to the recording start position,
The cap 62 and the blade 61 are in the same position as the wiping position described above. As a result, the ejection orifice surface of the recording head 65 is wiped during this movement as well. The above-mentioned movement of the print head to the home position is not limited to the end of printing or recovery of ejection, but also the movement of the print head to the home position adjacent to the print area at predetermined intervals while the print head moves across the print area for printing. However, along with this movement, the above-mentioned wiping is performed.

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, 40 is an ink storage section, for example, an ink bag, which stores ink for supply, and a rubber stopper 42 is provided at the tip thereof. By inserting a needle (not shown) into this stopper 42, the ink in the ink bag 40 can be supplied to the head. 44
is an absorber that receives waste ink. For the present invention, it is preferable for the ink storage part to have a surface in contact with the ink made of polyolefin, particularly polyethylene. The inkjet recording apparatus used in the present invention is not limited to one in which the head and ink cartridge are separate bodies as described above, but can also be suitably used in one in which they are integrated as shown in FIG.

In FIG. 6, reference numeral 70 denotes a recording unit, in which an ink storage section containing ink, such as an ink absorber, is housed, and the ink in the ink absorber passes through a plurality of orifices. The ink droplets are ejected as ink droplets from a head section 71 having the ink droplets. For the present invention, it is preferable to use polyurethane, cellulose, or polyvinyl acetal as the material for the ink absorber. Reference numeral 72 denotes an atmosphere communication port for communicating the inside of the recording unit with the atmosphere. This recording unit 70 is shown in FIG.
It is used in place of the recording head shown in , and is detachable from the carriage 66 .

[0021]

[Examples] Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples. In the text, parts and percentages are based on weight unless otherwise specified. Examples 1 to 6 and Comparative Examples 1 to 4 The components shown in Table 1 below were mixed, stirred thoroughly, and dissolved.
Inks of the present invention and comparative examples were prepared by pressure filtration using a fluoropore filter (trade name: manufactured by Sumitomo Electric Industries, Ltd.) with a pore size of 0.45 μm. Next, using the obtained inks of Examples 1 to 6 and Comparative Examples 1 to 4, an inkjet printer BJ-130 (product name:
(manufactured by Canon Inc.) was used to evaluate (1) clogging property evaluation, (2) print density evaluation, (3) print fixability evaluation, and (4) print quality evaluation. The results are shown in Table 2.

(1) Clogging resistance evaluation After filling the printer with the specified ink and printing alphanumeric characters continuously for 10 minutes, stop printing, put a cap on and leave for 10 days (standing conditions: 60°C , 10±5%R
After H), alphanumeric characters were printed again and the number of recovery operations until the initial printing condition could be reproduced was evaluated. ◎: The same printing as the initial one is possible without recovery operation ○: 1 to 5
The same printing as the initial one is possible after 11 recovery operations △: The same printing as the initial one is possible after 6 to 10 recovery operations ×: The same printing as the initial one is possible after 11 or more recovery operations (2) Print density Evaluation After alphanumeric characters and solid areas were printed on commercially available high-quality paper, the print density was measured using Macbeth RD915 (trade name: manufactured by Macbeth Co., Ltd.) after being left for one hour or more. ◎: Print density was 1.35 or more. Good: Print density was 1.30 or more and less than 1.35. Δ: Print density was 1.25 or more and less than 1.30. ×: Print density was less than 1.25.

(3) Evaluation of print fixation The print drying properties were evaluated at 5, 15, 25, and 35 after printing alphanumeric characters on commercially available continuous slip paper using a printer.
After a few seconds, it was rubbed with a filter paper (No. 2 (trade name) manufactured by Toyo Roshi Co., Ltd.), and judgment was made based on the number of seconds until the printed area was no longer stained (measured at 20±5° C., 50±10% RH). ◎: Dirt is not noticeable after 5 seconds. ○: Dirt is not noticeable after 15 seconds. △: Stains are not noticeable after 25 seconds. ×: Stains are not noticeable after 35 seconds. (4) Evaluation of printing quality Alphanumeric characters were printed using a printer on commercially available high-quality paper, and after being left for more than 1 hour, the sharpness of the characters and the degree of whisker-like bleeding caused by the characters were evaluated using a microscope and visually. ◎: Characters are sharp and there are no whisker-like blurs. ○: Characters are sharp, but some whisker-like blurring occurs. △: Characters lack sharpness. Or there are many whisker-like blurs. ×: Characters lack sharpness and have many whisker-like blurs.

[Table 1] Table 1

[Table 2] Continuation of Table 1

[Table 3] Table 2

[0024]

Effects of the Invention As explained above, according to the present invention, it is possible to improve the solidification prevention property of ink, the clogging prevention property, and the general use of general paper commonly used in offices such as copy paper, report paper, notebooks, stationery, and recycled paper. It is possible to record with high density and high quality on plain paper and other recording materials. Further, according to the ink of the present invention, highly reliable recording can be performed without clogging of the pen tip of a writing instrument or the nozzle of an inkjet head.

[0025]

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a head section of an inkjet recording apparatus.

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

FIG. 3 is an external perspective view of a multi-headed head shown in FIG. 1;

FIG. 4 is a perspective view showing an example of an inkjet recording device.

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

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

[Explanation of symbols]

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

Claims (14)

[Claims] 1. An ink comprising a recording agent and a liquid medium for dissolving or dispersing the same, characterized in that the ink contains both an organic amine salt of a dicarboxylic acid and an alkylamine. 2. An inkjet recording method for recording on a recording material by ejecting ink droplets from an orifice according to a recording signal, wherein the ink is the ink according to claim 1. . 3. The inkjet recording method according to claim 2, wherein ink droplets are ejected by applying thermal energy to the ink. 4. A recording unit comprising an ink storage 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. 5. The head unit includes a head that applies thermal energy to the ink to eject ink droplets.
Recording unit described in. 6. The recording unit according to claim 4, wherein the ink storage portion is made of polyurethane, cellulose, or polyvinyl acetal. 7. An ink cartridge comprising an ink accommodating portion containing ink, wherein the ink is
An ink cartridge characterized by being the ink described in . 8. The ink cartridge according to claim 7, wherein the ink storage portion has a liquid contact surface made of polyolefin. 9. An inkjet recording apparatus comprising a recording unit having an ink storage section containing ink and a head section for ejecting the ink as ink droplets, wherein the ink is the ink according to claim 1. An inkjet recording device characterized by: 10. The inkjet recording apparatus according to claim 9, wherein the head section includes a head that applies thermal energy to the ink to eject ink droplets. 11. The inkjet recording apparatus according to claim 10, wherein the ink storage portion is made of polyurethane, cellulose, or polyvinyl acetal. 12. An inkjet recording apparatus comprising a recording head for ejecting ink droplets, an ink cartridge having an ink storage section containing ink, and an ink supply section for supplying ink from the ink cartridge to the recording head. An inkjet recording apparatus, wherein the ink is the ink according to claim 1. 13. The ink jet recording apparatus according to claim 12, wherein the recording head is a head that applies thermal energy to ink to eject ink droplets. 14. The inkjet recording apparatus according to claim 12, wherein the ink storage portion has a liquid contact surface made of polyolefin.