JPH04211473A - Ink, method for ink jet recording using the same and apparatus using the same ink - Google Patents

Abstract

PURPOSE:To obtain an ink capable of improving its bleeding and delayed drying properties of records in recording on plain paper, having high printing quality and safety and hardly causing clogging of head nozzles by blending a specific cyclohexanol derivative with other components. CONSTITUTION:The objective ink is obtained by blending a compound expressed by the formula [R1 and R3 are H or 10C or less C alkyl or alkoxy, sulfonic acid (salt), nitro, OH, carboxyl, amino or derivative thereof, provided that R1 and R2 will not simultaneously be H] in an amount of about 0.01-30wt.% (especially preferably 0.2-5wt.%) with other components.

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 specifically to coated paper specially prepared for inkjet use, as well as to general office and home use. Using this ink, it is possible to record high-definition and high-quality images even on uncoated paper, so-called plain paper, such as copy paper, report paper, notebooks, stationery, bond paper, continuous slip paper, etc. The present invention relates to an inkjet recording method and a device using such ink.

0002

BACKGROUND OF THE INVENTION Conventionally, various compositions of inkjet inks have been reported. 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, a lot of bleeding may occur, or when ink is filled into an inkjet head, depending on the structural conditions of the head, the ink may recede from the orifice surface and ejection may not occur. Or,
On the other hand, problems such as the entire orifice surface becoming wet and ink not being ejected were observed. Furthermore, Japanese Patent Application Laid-Open No. 56-57862 proposes a method of making the pH of the ink strongly alkaline, but this method is dangerous if the ink is touched with one's hands, and also contains certain sizing agents. paper using, for example,
Neutral paper and the like have drawbacks such as bleeding and drying properties which may not be good. Various improvements have been attempted in addition to the above, but so far there is no ink that has been found to fully solve all of the problems of bleeding, drying, and ink safety, as well as clogging. The current situation is that this is not the case.

0004

[Problems to be Solved by the Invention] Therefore, the purpose of the present invention is to provide uncoated paper such as copy paper, report paper, notebook paper, stationery paper, bond paper, and continuous slip paper, so-called ordinary To provide an ink that solves the problems of ink bleeding and slow drying of recorded matter when recording on paper and has excellent printing quality, an inkjet recording method using the same, and a device using the ink. Another object of the present invention is to provide an ink that is highly safe for use in offices and homes, an inkjet recording method using the same, and equipment using the ink. Still another object of the present invention is to provide an ink that is less likely to cause clogging in the nozzles of an inkjet head and has excellent reliability, an inkjet recording method using the same, and a device using such an ink.

[0005]

[Means for Solving the Problems] The above object is achieved by the following present invention. That is, the present invention provides an ink containing a recording agent and a liquid medium for dissolving or dispersing the recording agent, which is characterized by containing a compound represented by the following general formula (I), and an inkjet recording method using the same. and devices using such ink.

[Formula 2] (However, R1 and R2 in the formula are each independently a hydrogen atom, an alkyl group having 10 or less carbon atoms, or an alkoxy group,
It is selected from the group consisting of a sulfonic acid group or a salt thereof, a nitro group, a hydroxyl group, a carboxyl group, an amino group, or a derivative thereof, and R1 and R2 are not hydrogen atoms at the same time. )

[0006]

[Function] In order to improve the bleeding, drying properties and permeability of ink on plain paper, the present inventors have conducted intensive studies on various ink compositions, and have found that the composition contains a compound represented by the above general formula (I). We discovered that the ink is well-balanced in terms of bleeding and permeability, has no adverse effects on clogging prevention, and is highly reliable with no problems in terms of safety. This led to the invention. In other words, according to the research conducted by the present inventors, the bleeding and permeability of ink on plain paper is good depending on the type of paper when a surfactant such as that used in normal ink is used. In contrast, when the compound represented by the above general formula (I) used in the present invention is used, the quality of the paper varies depending on the type of paper. It is possible to obtain extremely good results in that stable recording with little difference in values can be obtained.

[0007] The reason for this is that ink bleeding and permeability are largely controlled by the phenomenon of wetting at the interface between ink droplets and paper, but when a surfactant is used, Whereas good results cannot be obtained because the surface and internal parts of the ink droplet have different wetting properties, with the ink of the present invention, such a problem is unlikely to occur, and furthermore, the present invention This seems to be because the ink has an exquisitely balanced relationship between the sizing agent added to the surface or inside of the paper and the ink, making it compatible with plain paper.

[0008]

[Preferred Embodiments] Next, the present invention will be explained in more detail by citing preferred embodiments. The compound represented by the general formula (I) used in the present invention and which mainly characterizes the present invention is a derivative of cyclohexanol, and all of them can be obtained by conventionally known methods. Preferred specific examples of the compound represented by the above general formula (I), represented by R1 and R2 in the above general formula (I), are as follows, but the present invention is not limited to these specific examples. Regarding R1 and R2 shown in the following table, R1
is located at the para position with respect to the hydroxyl group, and R2 is located at the ortho position.

[0009]

The compound represented by the general formula (I) used in the present invention was derived as a result of intensive research by the present inventors in selecting R1 and R2. For example, when an alkyl group or alkoxy group having 11 or more carbon atoms is introduced as R1 or R2, although the permeability on paper is good, problems may arise in terms of bleeding, etc. The performance was significantly inferior to that of the previous model. The amount of the compound represented by the general formula (I) added to the ink varies depending on the pigment used and other liquid medium components used together, but it is preferably about 0.01 to 30% by weight in the ink. The proportion is 0.1 to 10% by weight, more preferably 0.2 to 5% by weight.

The ink of the present invention is characterized in that it contains a compound represented by the above general formula (I) together with a recording agent, but it also contains water and common organic solvents used in conventionally known inks. For example, as organic solvents, carbonaceous solvents such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-pentanol, etc. Alkyl alcohols of numbers 1 to 5; amides such as dimethylformamide and dimethylacetamide;
Ketones or keto alcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; oxyethylene or oxy such as diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol, and polypropylene glycol Propylene addition polymers; alkylene glycols in which the alkylene group has 2 to 6 carbon atoms, such as ethylene glycol, propylene glycol, trimethylene glycol, butylene glycol, 1,2,6-hexanetriol, hexylene glycol; thiodi 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; triethylene glycol dimethyl (or ethyl) ether, tetra Examples include lower dialkyl ethers of polyhydric alcohols such as ethylene 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 2% to 50% by weight, preferably 2% to 30% based on the total weight of the ink. Although the above-mentioned media can be used alone or in mixtures, the most preferred liquid medium composition consists of water and one or more organic solvents, where the solvent is at least one water-soluble high-boiling organic solvent, e.g.
It contains polyhydric alcohols such as diethylene glycol, triethylene glycol, and glycerin.

Recording agents constituting the ink of the present invention include direct dyes, acid dyes, food dyes, basic dyes, reactive dyes, disperse dyes, vat dyes, soluble architectural dyes, reactive disperse dyes, oil dyes, and various other dyes. Examples include pigments, and among them, water-soluble dyes are particularly preferred in terms of ink performance. The content of these recording agents is determined depending on the type of liquid medium component, the characteristics required of the ink, etc., but generally it is about 0.2 to 20% by weight in the total amount of ink, preferably about 0.2 to 20% by weight. 0.5
The proportion is 10% to 10%, more preferably 1 to 5%. The main components of the ink of the present invention are as described above, but various other dispersants, surfactants, viscosity modifiers, surface tension modifiers, fluorescent brighteners, etc. may be added within the range that does not impede the achievement of the purpose of the present invention. It can be added as needed.

For example, viscosity modifiers such as polyvinyl alcohol, celluloses, and water-soluble resins; various cationic, anionic, or nonionic surfactants; surface tension modifiers such as diethanolamine and triethanolamine; pH modifiers using buffer solutions; ; Antifungal agents, etc. can be mentioned. In addition, in order to prepare ink used in inkjet recording methods that charge the ink, lithium chloride,
A resistivity adjuster such as inorganic salts such as ammonium chloride and sodium chloride is added. The ink of the present invention is particularly suitable when applied to an inkjet recording method in which ink is ejected by a bubbling phenomenon of the ink caused by thermal energy, and the ink is said to be extremely stable and free from the generation of satellite dots. It has characteristics. However, in this case, thermal properties (e.g., specific heat, coefficient of thermal expansion,
(thermal conductivity, etc.) may also be adjusted.

Furthermore, the ink of the present invention solves the problem of ink bleeding when recorded on plain paper, dryness and permeability of the recorded material, and at the same time improves matching with the inkjet head. Its physical properties include a surface tension of 30 to 68 dyne/c at 25°C.
It is desirable that the viscosity is 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. % by weight or less, more preferably 75% by weight or less
It is preferable that the amount is from 95% by weight to 95% 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 inkjet 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.

A recording head 65 has an ejection energy generating means and performs recording by ejecting ink onto a recording material facing the ejection orifice surface on which the ejection orifices are arranged, and a recording head 66 is 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 through 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, which houses an ink storage section containing ink, such as an ink absorber, 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 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 used in place of the recording head shown in FIG. 4, and is detachable from the carriage 66.

[0022]

[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 5 After mixing the following components and stirring for 5 hours, the pH was adjusted to 7.5 with a 0.1% aqueous solution of sodium hydroxide, and a membrane filter with a pore size of 0.22 μm (trade name Fluoro) was added. The mixture was filtered under pressure using a pore 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, an inkjet printer BJ-130 (trade name: manufactured by Canon), which uses a heating element as an ink ejection energy source, was used as an inkjet recording device, and commercially available copy paper was used. and recording on bond paper, and the fixation of the resulting recorded material and the incidence of bleeding,
Clogging resistance and frequency response during reprinting after printing was paused were evaluated. The results are shown in Table 1.

Ink A C. I. direct yellow 86
2
Part diethylene glycol

15 parts Compound example 1 of general formula (I)

Part 1 Water

82 parts ink B C. I. acid red 35

Part 2 Glycerin

10 parts Compound example 6 of general formula (I)
1.5 parts ethylene glycol
5.5 parts water


81 parts ink C C. I. hood black 2

Part 3 Triethylene glycol

10 parts N-methyl-2-pyrrolidone

Part 2 Compound example 2 of general formula (I)

Part 1 Water


84 parts ink D C. I. direct blue 199
2.5 parts
Polyethylene glycol (molecular weight 300)
5 parts diethylene glycol
10
Part Triethylene glycol monomethyl ether
Part 2 Triethanolamine
0.5
Part Compound Example 13 of General Formula (I)

Part 3 Water

77 parts ink E C. I. direct black 154
Part 2 Thiodiglycol

6 parts diethylene glycol

Part 9 Compound example 9 of general formula (I)
Part 1 Water


82 copies

Comparative Examples 1 to 4 In the same manner as Examples 1 to 5 using the following components,
Inks F to I of Comparative Examples 1 to 4 were obtained, and various evaluations were performed in the same manner as in the Examples. The results are shown in Table 1. Ink FC. I. direct yellow 86
2
Part diethylene glycol

Part 15 Water

83 parts ink GC. I. hood black 2

Part 3 Diethylene glycol

10 parts triethylene glycol

10 parts Nonionic surfactant (trade name Nissan Nonion P223, manufactured by NOF)


0.5 part water

76.5
Part ink HC. I. acid red 35

Part 2 Glycerin

10 parts Compound of general formula (I) (R1=C11H23, R2=H)
1.5 parts ethylene glycol

5.5 parts water

81
Part Ink I C. I. hood black 2

Part 3 Triethylene glycol

10 parts N-methyl-2-pyrrolidone

2 parts ethanol

Part 1 Water

84 copies

[0025]

[Table 1]

*1 Evaluation of fixability 10 seconds and 30 seconds after printing on commercially available copy paper and bond paper, rub the printed area with filter paper (trade name: No. 5C, manufactured by Toyo Roshi) and perform the following procedure. evaluated (25℃, 60%
(Evaluated under RH environmental conditions). ◎...No fading in 10 seconds ○...Fading in 10 seconds Small △...Fading in 30 seconds Small ×...Fading in 30 seconds Large *2 Smearing incidence rate Regarding the incidence of bleeding, see the following table for printing on commercially available copy paper and bond paper. After printing 300 dots in a discontinuous manner, it was left for more than an hour, and then the number of dots that had blurred was counted using a microscope, and the percentage of the total number of dots was expressed as a percentage and evaluated as follows (25 (printed under environmental conditions of ℃ and 60% RH). ○…10% or less △…11-30% ×…31% or more

*3 Clogging property: Clogging property refers to the property of clogging when reprinting after printing has been temporarily stopped.
After printing alphanumeric characters continuously for 0 minutes, stop printing, leave it for 10 minutes with no cap etc., and then print alphanumeric characters again. Are there any defects such as fading or chipping of characters? (Evaluation under environmental conditions of 25° C. and 60% RH). ○…No defects from the first character. △...Part of the first character is faded or missing. ×…The first character cannot be printed at all. *4 Frequency response The printed condition of the obtained printed matter, that is, the state of fading, white spots, and poor impact points such as splash and wobbling, was observed and evaluated with the naked eye. ◎...The tracking state of the ink with respect to the frequency was good, and no blurring, white spots, or poor landing points were observed in solid character printing. ○...The tracking state of the ink with respect to the frequency is almost good, and no blurring, white spots, or poor landing points are observed in character printing, but slight blurring is observed in solid printing. △...No fading or white spots are observed in character printing, but some impact point defects are observed. Also, solid printing may cause fading,
White spots can be seen in about 1/3 of the entire solid print. x: There are many scratches and white spots in solid printing, and there are also many scratches and poor landing points in character printing.

[0028]

[Effects of the Invention] As explained above, the ink of the present invention does not bleed onto plain papers such as copy paper, report paper, notebooks, stationery bond paper, and continuous slip paper, which are generally used in offices. This makes it possible to record with excellent quality and good fixing properties. Furthermore, according to the present invention, it is possible to obtain ink that is highly safe even when used in offices and homes. Furthermore, according to the ink of the present invention,
It is possible to perform highly reliable recording without clogging of the nozzles of the inkjet head, and the response to frequency is particularly good for types of recording that eject ink by the bubbling phenomenon of ink caused by thermal energy. . Furthermore, by using the ink of the present invention, it is possible to provide highly reliable equipment.

[0029]

[Brief explanation of the drawing]

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 (11)

[Claims] 1. An ink comprising a recording agent and a liquid medium for dissolving or dispersing the same, the ink comprising a compound represented by the following general formula (I). [Formula 1] (However, R1 and R2 in the formula are each independently a hydrogen atom, an alkyl group having 10 or less carbon atoms, or an alkoxy group,
It is selected from the group consisting of a sulfonic acid group or a salt thereof, a nitro group, a hydroxyl group, a carboxyl group, an amino group, or a derivative thereof, and R1 and R2 are not hydrogen atoms at the same time. ) 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 the recording material is uncoated paper. 4. The inkjet recording method according to claim 2, wherein ink droplets are ejected by applying thermal energy to the ink. 5. 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. 6. The head unit includes a head that applies thermal energy to the ink to eject ink droplets.
Recording unit described in . 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. An inkjet recording apparatus comprising an ink storage unit containing ink and a recording unit having a head unit for ejecting the ink as ink droplets, wherein the ink is the ink according to claim 1. An inkjet recording device characterized by: 9. Claim 8, wherein the head section includes a head that applies thermal energy to the ink to eject ink droplets.
The inkjet recording device described in . 10. 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. 11. The ink jet recording apparatus according to claim 10, wherein the recording head is a head that applies thermal energy to ink to eject ink droplets.