JPH04202573A - Ink, method for ink jet recording using the same and apparatus using the same ink - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an ink, an inkjet recording method using the same, and a device using such an ink, and more specifically, to an ink that is water resistant even when printed on plain paper. The present invention relates to an ink that provides an excellent image and also provides an image with improved indoor discoloration when printed on coated paper, an inkjet recording method using the same, and an apparatus using such an ink.

(Prior Art) Conventionally, inkjet inks with a wide variety of compositions have been reported. In recent years, the composition and physical properties of ink have been improved to enable good recording even on plain papers commonly used in offices, such as copy paper, report paper, notebooks, stationery, pound 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 for the purpose of preventing drying and clogging, but when printing on various recording materials using such ink, Since the coloring material used in printing is a water-soluble dye, there is a problem in that the printed image smudges due to sweat, water droplets, etc., making the printed image unclear or damaged.

Furthermore, in order to form clear full-color images, coated paper is often used, but in this case sufficient light resistance and weather resistance are required. Particularly, it is a big problem that discoloration progresses even indoors where there is no sunlight.

(Problems to be Solved by the Invention) Therefore, the object of the present invention is to provide an ink which has excellent durability of printed images even when printed on various types of plain paper, and which shows little discoloration even when printed on coated paper. The object of the present invention is to provide an inkjet recording method using this ink and a device using such ink.

(Means for solving problems) The above objects are achieved by the present invention as described below.

That is, the present invention provides an ink comprising a small amount of water, a water-soluble organic solvent, and a dye, which is characterized by containing a compound represented by the following general formula as the dye, an inkjet recording method using the same, This is a device using such ink.

(However, R, , R, and R3 are each a hydrogen atom or SO,
M, R4 is a hydrogen atom, OCHs, NH,, NHC
ONHz or SO, M, R6 is a hydrogen atom or SO
, M, R6 represents a hydrogen atom or NH2, R1 represents a hydrogen atom, CHl or 0CHa, R8 represents a hydrogen atom, C00M or SO,M, and R4 and R6 both represent NH
, then R6 is a hydrogen atom, R1 is C00M, and M
indicates an alkali metal, ammonium, or organic ammonium, and m is O or 1) (Function) By using a dye with a specific structure as the ink coloring material, the printed image remains unchanged even when printed on various types of plain paper, etc. It is possible to provide an excellent ink that has excellent durability and little discoloration even when printed on coated paper, an inkjet recording method using the same, and a device using such an ink.

(Preferred Embodiments) Next, the present invention will be described in more detail by citing preferred embodiments.

The dye of the general formula used in the present invention and which mainly characterizes the present invention may be any dye as long as it is included in the general formula (and can be used alone or as a mixture, and in some cases may be used in combination with other dyes not included in the above general formula.Among the dyes of the above general formula, particularly preferred dyes are as exemplified below.

(Left below) The content of these dyes is determined depending on the type of liquid medium components, the characteristics required of the ink, etc., but numerically it is about 0.2 to 20% by weight in the total amount of ink. %, preferably 0.
The proportion is 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 bathable organic solvent, and the water used is not only ordinary water but also preferably deionized water. Examples of organic solvents include:
Alkyl alcohols having 1 to 5 carbon atoms such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, see-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-pentanol, or these. Halogenated rust conductors; amides such as dimethylformamide and dimethylacetamide; ketones or keto alcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, Oxyethylene or oxypropylene addition polymers such as tripropylene glycol, polyethylene glycol, 'polypropylene glycol; ethylene glycol, propylene glycol, trimethylene glycol, butylene glycol, 1,2.6
- Alkylene glycols in which the alkylene group has 2 to 6 carbon atoms such as hexanetriol and hexylene glycol; thiodiglycol; glycerin; ethylene glycol monomethyl (or ethyl) ether, diethylene glycol monomethyl (or ethyl) ether, triethylene Lower alkyl ethers of polyhydric alcohols such as glycol monomethyl (or ethyl) ether; lower dialkyl ethers of polyhydric alcohols such as triethylene glycol dimethyl (or ethyl) ether and tetraethylene glycol dimethyl (or ethyl) ether; sulfolane; Examples include 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, preferably 2% to 3% by weight based on the total weight of the ink.
The range is 0%. The above-mentioned media can be used alone or in mixtures.

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; cationic, anionic, or nonionic surfactants; surface tension modifiers such as jetanolamine and triethanolamine; pH modifiers using buffers; Antifungal agents and the like 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 in ejection and free from the generation of satellite dots. It has characteristics.

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. It is desirable that the surface tension at 25° C. is adjusted to 30 to 68 dyne/cm and 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, preferably 60% by weight or more. suitable.

The ink of the present invention is particularly suitable for use in an inkjet recording method in which recording is performed by ejecting droplets under 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(a), 1(b), and 2.

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 has a protective film 1 formed of silicon oxide or the like.
6. It consists of aluminum electrodes 17-1, 17-2, a heat generating low antibody layer 18 formed of nichrome or the like, a heat storage layer 19, and a substrate 20 with good heat dissipation properties such as alumina.

The ink 21 has reached a discharge orifice (micropore) 22, and a meniscus 23 is formed by 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 a meniscus. 23 protrudes, the ink 21 is ejected, becomes a recording droplet 24 from the orifice 22, and flies toward the recording material 25. FIG. 2 shows an external view of a multi-head in which a large number of heads shown in FIG. 1(a) are arranged. The multihead has a glass plate 27 having a multiplier 26 and a glass plate 27 as shown in FIG.
A heat generating head 28 similar to that described in a) is attached in close contact with the heat generating head 28.

1(a) is a cross-sectional view of the head 13 along the ink flow path, and FIG. 1(b) is a cross-sectional view taken along the line A-B in FIG. 1(a).

FIG. 3 shows an example of an ink jet recording apparatus incorporating such a head.

In FIG. 3, 61 is a blade serving as a wiping member, one end of which is held by a blade holding member and becomes a fixed end, forming a cantilever. 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 ink absorber provided adjacent to the blade 61;
Like the blade 61, it is held in a protruding form in the movement path of the recording head. The blade 61 and cap 62
The absorber 63 constitutes 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 is a recording head that has an ejection energy generating means and performs recording by ejecting ink onto a recording material facing the ejection orifice surface on which ejection ports are arranged, and 66 is a recording head that mounts the print head 65 and moves the print head 65. It is a carriage for carrying out. The carriage 66 is slidably engaged with a guide shaft 67, and a portion of the carriage 66 is connected to a belt 6 driven by a motor 68.
9 (not shown). As a result, carriage 6
6 can be moved along the guide shaft 67, and the recording head 65 can move the recording area and its adjacent area.

Reference numeral 51 is a paper feed section for inserting a recording material, and 52 is a paper feed row 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. 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.

When the recording head 65 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,
During this movement as well, the ejection orifice surface of the recording head 65 is wiped.

The above-mentioned sb to the home position of the print head is not only performed at the end of printing or when recovering ejection (but also when the print head moves to the home position adjacent to the print area at predetermined intervals while moving across the print area for printing). The wiping is performed along with this movement.

FIG. 4 is a diagram showing an example of an ink cartridge containing ink that is supplied to the head via an ink supply member, such as 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 plug 42, the ink in the ink bag 4o can be supplied to the head. , 44 is an ink 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 device used in the present invention includes:
It can be suitably used not only in the case where the head and ink cartridge are separate bodies as described above, but also in one in which they are integrated as shown in FIG.

In FIG. 5, reference numeral 70 denotes a recording unit, in which an ink containing part containing ink, for example, 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 as the material for the ink absorber.

Reference numeral 72 denotes an atmosphere communication port for communicating the inside of the cartridge with the atmosphere.

This recording unit 7o is used in place of the recording head shown in FIG. 3, and is detachable from the carriage 66.

(Example) Next, the present invention will be explained in more detail by giving examples and comparative examples. In the text, parts and percentages are based on weight unless otherwise specified.

Examples 1 to 10 and Comparative Examples 1 to 2 The following components were mixed and dissolved, and filtered under pressure using a filter with a pore size of 1 μm to obtain inks of the present invention and comparative examples shown in Table 1 below.

Diethylene glycol 25 parts Pure water
72 parts Exemplary dye (1) 3 parts Diethylene glycol 30 parts Pure water
67 parts of the above exemplified dye (
2) 3 parts diluted ethylene glycol 20 parts pure water
76 parts Exemplary dye (4) 4 parts Blood clot ±A Glycerin 20 parts Pure water
75 parts of the above exemplified dye (
6) 5 parts husband's blood 1 triethylene glycol 25 parts ethylene glycol monomethyl ether 15 parts pure water
55 parts of the above exemplified dye (9
) 5 parts Glycerin 20 parts Pure water
76 parts of the above-mentioned exemplary dye (
10) 4 parts suspended euglycerin 15 parts N-methyl-2-pyrrolidone 10 parts pure water
71 parts Exemplary dye (13)
4 parts saturated triethylene glycol 20 parts ethylene glycol monomethyl ether 15 parts pure water
60 parts of the above exemplified dye (1
4) 5 parts diluted ethylene glycol 25 parts N-methyl-2-pyrrolidone 10 parts pure water
60 parts of the above exemplified dye (15
) 4 parts diethylene glycol 25 parts polyethylene glycol 10 parts N,N-dimethylimidazolidinone 5 parts pure water
57 parts Exemplary dye (18)
3 parts Nidiethylene glycol 30 parts pure water
67 parts C, 1, Food Black 1 3 parts Comparison L Ethylene glycol 20 parts Pure water
76 parts C, 1, food black 2 4 parts Next, thermal energy was applied to the ink in the recording head using the inks of Examples 1 to 10 above. ! Solid printing is performed using an on-demand type multi-head recording device (manufactured by Canon ■, BJ-130) that generates droplets and performs recording.
A printed piece with a size of OX20 mm was created. The paper used was Canon's recommended paper for NP-6150, Canon NP-Dry, Neusidler paper, and Proberbond paper. The optical densities of all printed matter were in the range of 1.30 to 1.45. After immersing this printed piece in still water at 20°C for 5 minutes, the water resistance was evaluated by measuring the rate of decrease in optical density.The rate of decrease was 15% or less in all cases, indicating excellent water resistance. Ta. On the other hand, when the water resistance was similarly examined using the inks of Comparative Examples 1 and 2, the reduction rate of optical density was 50% or more in all cases.

In addition, the color difference (ΔE″ab) of the print before and after the test was determined by printing in the same manner on Canon Color Bubble Jet Copier designated paper and leaving the print in a test chamber where the ozone concentration was maintained at 30 ppm for 2 hours. Measured. As a criterion, ○: Δ
E”ab<5, △:5≦ΔE”ab≦10. X:ΔE
When evaluated as "ab>10, all the printed matter using the inks of Examples 1 to 10 were ○(ΔE"ab<5
), the discoloration was not noticeable. On the other hand, Comparative Example 1 had a Δ and relatively little discoloration, but Comparative Example 2 had an X and had severe discoloration.

(Effects) As is clear from the above explanation, according to the present invention, by selecting a dye with a specific structure as the coloring material of the ink, it is possible to achieve excellent water resistance on plain paper and color fastness on coated paper. An ink is provided that provides a print.

[Brief explanation of the drawing]

FIG. 1(a) and FIG. 1(b) are a longitudinal cross-sectional view and a cross-sectional view of a head section of an inkjet recording apparatus. FIG. 2 is an external perspective view of a multi-head head shown in FIG. 1. FIG. 3 is a perspective view showing an example of an inkjet recording apparatus. FIG. 4 is a longitudinal sectional view of the ink cartridge. FIG. 5 is a perspective view of the recording unit. 61: Wiping member 62: Cap 63: Ink absorber 64: Ejection recovery section 65: Recording head 66: Carriage Fig. 1(a) Fig. 1(b) Fig. 2 Fig. 3 Fig. 4

Claims (10)

[Claims] (1) An ink comprising at least water, a water-soluble organic solvent, and a dye, the ink containing a compound represented by the following general formula as the dye. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, R_1, R_2 and R_3 each represent a hydrogen atom or SO_3M, R_4 represents a hydrogen atom, OCH_3, N
H_2, NHCONH_2 or SO_3M, R_
5 represents a hydrogen atom or SO_3M, R_5 represents a hydrogen atom or NH_2, R_7 represents a hydrogen atom, CH_3 or OCH_3, R_8 represents a hydrogen atom, COOM or S
O_3M, when R_4 and R_6 are both NH_2, R_5 is a hydrogen atom and R_8 is COOM, M represents an alkali metal, ammonium or organic ammonium, and m is 0 or 1) (2) An inkjet recording method in which recording is performed 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. (5) The recording unit according to claim 4, wherein the head section is a head that applies thermal energy to the ink to eject ink droplets. (6) An ink cartridge comprising an ink storage portion containing ink, wherein the ink is the ink according to claim 1. (7) In an inkjet recording device including an ink storage unit containing ink and a recording unit having a head unit for ejecting the ink as ink droplets, the ink is the ink according to claim 1. Characteristic inkjet recording device. (8) The inkjet recording apparatus according to claim 7, wherein the head section is a head that applies thermal energy to the ink to eject ink droplets. (9) In 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 characterized in that the ink is the ink according to claim 1. (10) The inkjet recording apparatus according to claim 9, wherein the recording head is a head that applies thermal energy to the ink to eject ink droplets.