JPH1180634A - Ink and ink jet recording method using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ink having good startup properties, excellent resistance to colorant fixation at nozzle ends and not problematic in nozzle plugging by including a colorant, dithioglycol, a polyhydric alcohol and a specified compound. SOLUTION: 3-15 wt.%, desirably 5-10 wt.% dithioglycol, 0.5-10 wt.%, desirably 1.0-7.0 wt.% colorant, optionally 3-20 wt.% polyhydric alcohol selected among glycerol, ethylene glycol and diethylene glycol, 1-15 wt.% compound of the formula (wherein R1 to R4 are each H or an alkyl), 2-60 wt.%, desirably 5-25 wt.% water-soluble organic solvent, 10-90 wt.% water are mixed with each other in such amounts that the total amount of the dithioglycol and the polyhydric alcohol is 5-30 wt.%, and the total amount of the dithioglycol and the compound of the formula is 5-30 wt.%. Thus, an ink jet recording ink which can be stably delivered can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink, particularly to a highly reliable ink suitable for ink jet recording and an ink jet recording method using the same.

[0002]

2. Description of the Related Art In an ink jet recording method, recording is performed by flying small ink droplets and attaching the ink to a recording medium such as paper. In particular, Japanese Patent Publication No. 61-59911
JP, JP-B-61-59912, JP-B-61-59912
According to an ink jet recording method disclosed in Japanese Patent Application Laid-Open No. 59914, in which an electrothermal converter is used as a discharge energy supply unit and droplets are generated by applying thermal energy to ink to generate bubbles, High-density multi-orifices can be easily realized, and high-resolution and high-quality images can be recorded at high speed. In particular, in recent years, the resolution of ink jet recording has been increased, and accordingly, the amount of ink droplets ejected from a single nozzle has been decreasing in comparison with the related art.

On the other hand, as an ink composition of a conventional ink jet recording method, an aqueous ink in which a dye and a pigment as a coloring material are dissolved or dispersed in a medium mainly containing water containing a water-soluble organic solvent is often used. Is coming. On the other hand, as described above, when the amount of ink droplets ejected from a single nozzle decreases, the use of these conventional aqueous inks for inkjet recording causes the following problems. That is, the relative coloring material concentration increases due to the evaporation of water in the ink at the nozzle tip, the ink viscosity increases, and the ink cannot be ejected normally. As a result, the so-called start-up characteristic is deteriorated such that the dot press becomes inaccurate or the dot diameter becomes small at the start of writing. And
Such a phenomenon is particularly remarkable in a low humidity environment in which evaporation of ink from the nozzle tip is promoted or in a low temperature environment in which ink viscosity increases. Further, another problem caused by water evaporation of the ink generated at the nozzle tip is that when the printer is left unused for a certain period of time, or
In the case where the ink tank and print head are integrated, when the print head itself is left detached from the printer, or when the ink tank and print head can be separated, the ink tank is removed from the printer. For example, clogging due to fixation of the coloring material generated at the nozzle tip due to evaporation of water, for example, when left in a state, may be mentioned.

[0004]

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned problems which have occurred particularly in aqueous inks for ink jet recording. That is, an object of the present invention is to maintain good start-up characteristics, particularly when used in ink jet recording, and to have excellent resistance to fixation of a coloring material at the nozzle tip (hereinafter, simply referred to as sticking resistance). An object of the present invention is to provide an excellent ink capable of performing stable ejection without clogging and an ink jet recording method using the same.

[0005]

The above object is achieved by the present invention described below. That is, the present invention is an ink containing at least a coloring material and dithiodiglycol, and an ink jet recording method using the ink.

The present inventors have eagerly studied the composition of an ink capable of exhibiting good start-up characteristics and sticking resistance even in ink jet recording in which a small amount of ink is ejected from a single nozzle. As a result of the study, the inventors have found that the addition of dithiodiglycol in the ink can improve the start-up characteristics and the sticking resistance of the ink, leading to the present invention. That is, when dithiodiglycol is contained in the ink, even at the nozzle tip of the ink jet recording apparatus, it is possible to effectively prevent the drying of the ink, so that the above-described excellent effects of the present invention are obtained. Conceivable.

Further, the effect of the present invention of improving the start-up characteristics and the sticking resistance of the ink becomes more remarkable when the composition of the ink is a system using a polyhydric alcohol in addition to the above dithiodiglycol. Also, in addition to dithiodiglycol and polyhydric alcohol, the effect is most remarkable when a so-called urea compound is used in combination, as represented by compound A represented by the following general formula. Do you get it. (In the above formula A, R _{1 to} R ₄ each represent a hydrogen atom or an alkyl group.) As a coloring material constituting the ink of the present invention, the water-soluble dyes or pigments described above are excellent. The effect is obtained.

[0008]

Next, the present invention will be described in detail with reference to preferred embodiments of the present invention. As described above, the ink of the present invention is characterized by containing at least a coloring material and dithiodiglycol, and preferably, a polyhydric alcohol is added thereto, and the dithiodiglycol and the polyhydric alcohol are used in combination. More preferably, a so-called urea-based compound represented by a compound A represented by the following general formula is added thereto, and when dithiodiglycol, a polyhydric alcohol and the compound A are used in combination, the start-up of the ink The effect of the present invention of improving the characteristics and the adhesion resistance becomes remarkable.

[0009] (In the above formula A, R _{1 to} R ₄ each represent a hydrogen atom or an alkyl group.)

The dithiodiglycol constituting the ink of the present invention is represented by (CH ₂ CH ₂ OH) ₂ S ₂ and has a boiling point of 282.
Although it is a colorless liquid having a viscosity of 47 cps and a temperature of preferably 3 to 15% by weight, more preferably 5 to 10% by weight, based on the total amount of the ink of the present invention. This content largely depends on the use and purpose of the ink, the kind of coloring material contained in the ink, and other components, but the content of dithiodiglycol in the ink of the present invention is less than 3% by weight. Cannot effectively prevent drying of the ink, and the effect of improving the startup characteristics and the anti-sticking property cannot be sufficiently obtained. On the other hand, when the content exceeds 15% by weight, when used for ink jet recording, the viscosity of the ink becomes high, and it becomes difficult to discharge the ink from the nozzles properly.

As described above, in the ink of the present invention,
In addition to the dithiodiglycol described above,
The start-up characteristics and sticking resistance
It can be further improved. Preferably used in the present invention
Specific examples of polyhydric alcohols include, for example, ethylene
Glycol, diethylene glycol, triethylene glycol
Coal, propylene glycol, glycerin, polyethylene
Len glycol and the like. Among these, guri
Serine, ethylene glycol, diethylene glycol
Those selected from the above are preferable in the present invention. Of course,
The present invention is not limited to these. Ink
The purpose and purpose, the type of color material contained in the ink, and other groups
These polyvalent alcohols largely depend on the components.
The content of the ink in the ink is based on the total amount of the ink.
Then, it is preferable to contain about 3 to 20% by weight.
Furthermore, dithiodiglycol contained in the ink and polyvalent
The total amount of alcohol is 5% of the total amount of ink.
It is preferred that the content be contained so as to be 30% by weight.
If the polyhydric alcohol content is less than 3% by weight,
It is difficult to obtain the effect of adding alcohol,
On the other hand, a total of dithiodiglycol and polyhydric alcohol
When the amount of the ink exceeds 30% by weight, the viscosity of the ink increases.
When used for ink jet recording,
It becomes difficult to discharge ink satisfactorily.

Further, the ink of the present invention contains a compound A represented by the following general formula in addition to the above dithiodiglycol, or a compound represented by the following general formula in addition to dithiodiglycol and a polyhydric alcohol. Compound A
Incorporation of further improves the start-up characteristics and the sticking resistance of the ink, and achieves stable ejection.
In particular, when a pigment is used as a coloring material of the ink, it is better to use dithiodiglycol, a polyhydric alcohol, and a compound A represented by the following general formula in combination. (In the above formula, R _{1 to} R ₄ each represent a hydrogen atom or an alkyl group.)

Specific examples of the compound A used in the present invention include urea compounds such as urea, trimethylurea and tetramethylurea. In the present invention, urea is preferable among these, but of course, the present invention is not limited to these. In the present invention, these compounds A are used in an amount of 1 to 1 with respect to the total amount of the ink.
It is preferable to contain it in the range of 5% by weight. Further, the amount of dithiodiglycol, polyhydric alcohol, and compound A contained in the ink is 5 to 5% with respect to the total amount of the ink, although it largely depends on the type of coloring material contained in the ink and other composition components. It is preferable to contain it so as to be 30% by weight. If the content of the compound A is less than 1% by weight, the effect of the combined use of the compound A cannot be sufficiently obtained. On the other hand, if the content exceeds 15% by weight, the discharge performance deteriorates, which is not preferable.

Next, components constituting the ink of the present invention will be described. First, as a coloring material used in the ink of the present invention, conventionally used water-soluble dyes and pigments can be used without any problem. For example, examples of the water-soluble dye include a dye containing at least one COOH group or a COSH group, and particularly preferably a dye having a COOH group. Specific examples will be described below.

For example, dyes represented by the following structural formulas (a) to (e) are mentioned, and specifically, exemplified compounds 1 to 31
Is preferably used in the present invention. In the dyes of the following structural formulas (a) to (e) and the exemplified compounds 1 to 31, a preferred form in the ink is one in which at least one of a COOH group and a COSH group is an ammonium salt. However, the counter ion is not limited to ammonium ion, and any conventionally known counter ion for anionic dyes such as sodium ion and lithium ion can be used.

[0016]

In the formula (a), Ar and Ar ₁ are each an aryl group or a substituted aryl group, and at least one of Ar and Ar ₁ has at least one substituent selected from a COOH group and a COSH group. And n is 0 or 1, J, J
₁ is a linking group independently selected from the following formulas (1), (2) and (3).

[0018] [In the formula (1), R ₅ is independently a hydrogen atom, an alkyl group, a substituted alkyl group, an alkoxy group, a halogen group, a CN
Groups, ureido groups and NHCOR ₆ groups, wherein R ₆ is a hydrogen atom, an alkyl group, a substituted alkyl group,
An aryl group, a substituted aryl group, an aralkyl group or a substituted aralkyl group. In the formula (2), T is independently an alkyl group, and W is independently a hydrogen atom, a CN group, CO 2
Selected from NR _{1 O} R ₁₁ groups, pyridinium groups and COOH groups, m is a C ₂ -C ₈ alkylene chain, and in the formula (3), B is a hydrogen atom, an alkyl group or a COOH group. R ₁₀ and R ₁₁ are each independently a hydrogen atom, an alkyl group or a substituted alkyl group. ]

In the formula (a), R ₁ , R ₂ , R ₃ and R ₄ are each independently a hydrogen atom, an alkyl group or a substituted alkyl group, L is a divalent linking group, X is independently a carbonyl group or a linking group selected from the following formulas (4), (5) and (6). [In the formulas (4), (5) and (6), each Z is OR ₇ , S
R ₇ or NR ₈ R ₉ , Y in the formula (5) is a hydrogen atom, a chlorine atom, a CN group or Z, and E in the formula (6)
Is a chlorine atom or a CN group, and R ₇ , R ₈ , R ₉
Is independently a hydrogen atom, an alkenyl group, a substituted alkenyl group, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, an aralkyl group or a substituted aralkyl group;
R ₈ and R ₉ may form a 5- or 6-membered ring together with the nitrogen atom to which they are bonded. Further, the compound of the above formula (a) does not have an SO ₃ H group (this term means a salt with free sulfonic acid or any base in the text and the structural formula). In some cases, at least two COOH groups and COSH
Having a group selected from the group consisting of
When it has an O ₃ H group, it has at least the same number of groups selected from COOH groups and COSH groups as the number of SO ₃ H groups. ｝

Preferred compounds among the compounds represented by the structural formula (a) are those in which Ar and Ar ₁ are an aryl group or a substituted aryl group having at least one carboxyl group as a substituent, and J and J ₁ are It is a group represented by the formula (1) or (2), and X is a compound represented by the formula (4) or (5). Specific examples of more preferable compounds represented by the structural formula (a) are shown below.

[0021]

[0022]

[0023]

[0024]

[0025]

[0026] ｛However, in the formula (b), J indicates the following formula (7). Ar ₁ and Ar ₂ in the formula (b) are each an aryl group or a substituted aryl group, and at least one of Ar ₁ and Ar ₂ has at least one substituent selected from a COOH group and a COSH group. R ₁ and R ₂ are independently a hydrogen atom, an alkyl group, a substituted alkyl group, an alkenyl group or a substituted alkenyl group, L is a divalent linking group, n is 0 or 1, X independently represents a carbonyl group or any of the following formulas (8), (9), and (10).

[0027]

[In the formulas (8), (9) and (10), Z is
Independently NR ₃ R ₄ , SR ₅ or OR ₅ , Y is independently a hydrogen atom, a chlorine atom, Z, SR ₆ or OR ₆ ;
E is independently a chlorine atom or a CN group. R ₃ , R ₄ , R ₅ and R ₆ each independently represent a hydrogen atom, an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an aryl group, a substituted aryl group, an aralkyl group or a substituted aralkyl group. And R ₃ and R ₄ may form a 5- or 6-membered ring together with the nitrogen atom to which they are attached. The compound represented by the formula (b) has a COOH group and C
The number of groups selected from OSH groups is at least the same as the number of SO ₃ H groups. ｝

Preferred among the compounds represented by the structural formula (b)
New compounds include Ar and Ar as substituents. ₁Is at least
Aryl or substituted ant having one carboxyl group
X is a carbonyl group or the formula (8) or
It is a compound having a group represented by (9). Structural formula
Specific examples of more preferred compounds represented by (b)
Is shown below.

[0030]

[0031]

[0032]

[0033]

[0034] 中 In the formula (c), Pc is a metal-containing phthalocyanine nucleus, and R ₁ , R ₂ , and R ₃ are each independently a hydrogen atom, an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an aralkyl group. Or a substituted aralkyl group, L is a divalent linking group, and X is independently a carbonyl group or the following formulas (11) to (13)

[0035]

[In the formulas (11) to (13), Z is independently NR ₄ R ₅ , SR ₆ or OR ₆ , and Y is independently a hydrogen atom, a chlorine atom, Z, SR ₇ or OR ₇ And E is independently a chlorine atom or a CN group, and R ₄ , R ₅ , R ₆ and R ₇ are each independently a hydrogen atom, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, an aralkyl Or a substituted aralkyl group, or R ₄ and R ₅ together with the nitrogen atom to which they are attached may form a 5- or 6-membered ring. G is a COSH group and C
A colorless organic group substituted by one or two groups selected from an OOH group, (t + q) is 3 to 4, and the compound (c) has at least one SO ₃ H group; It has the same number of groups selected from COSH and COOH groups. ｝

Preferred compounds among the compounds represented by the structural formula (c) are those wherein X is a carbonyl group or a group represented by the above formula (11) or (12) as a substituent and G is a carboxyl group. It is a compound having at least one substituted organic acid group. Specific examples of more preferred compounds represented by the structural formula (c) are shown below.

[0038]

[0039]

[0040] Wherein L represents a metal cation or hydrogen, and Pc is 3 to 4
And R ₁ represents hydrogen, an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an aralkyl group, or a substituted aralkyl group. R ₂ is hydrogen, an alkyl group, an alkoxy group, a halogen atom, or any substituted amino group. (T + q) is 3 to 4,
COOH is attached at position 2, 3, 5 or 6 in the formula (d). Specific examples of more preferable compounds represented by the structural formula (d) are shown below.

[0041]

[0042] (In the formula, Y is a hydrogen atom or SO ₃ H.)

Specific examples of more preferable compounds represented by the structural formula (e) are shown below.

When the water-soluble dye is used as a coloring material, the content of the dye is preferably
It is 0.5 to 10% by weight, more preferably 1.0 to 7.0% by weight. When the content of the water-soluble dye is less than 0.5% by weight, the obtained image density is too low.
If it exceeds 0% by weight, it is not preferable from the viewpoint of increasing the viscosity of the ink.

The following are examples of pigments used as coloring materials. The carbon black used for the black ink is a carbon black manufactured by a furnace method or a channel method, and has a primary particle diameter of 15 to 40 m.
μ, specific surface area by BET method is 50 to 300 m ² / g,
Those having a DBP oil absorption of 40 to 150 ml / 100 g, a volatile matter of 0.5 to 10%, and a pH of 2 to 9 are preferable. 2300, NO. 900, MCF8
8, NO. 33, NO. 40, NO. 45, NO. 5
2, MA7, MA8, NO. 2200B (Mitsubishi Kasei), RAVE 1255 (Colombia), REGA
L400R, REGAL330R, REGAL660
R, MOGUL L (Cabot), Color B
rack FW1, Color Black FW1
8, Color Black S170, Color B
luck S150, Printex 35, Prin
It is preferable to use a commercially available product such as tex U (manufactured by Degussa).

The pigment used for the yellow ink includes C.I. I. Pigment Yellow 1,
C. I. Pigment Yellow 2, C.I. I.
Pigment Yellow 3, C.I. I. Pigm
ent Yellow 13, C.I. I. Pigment
Yellow 16, C.I. I. Pigment Ye
llow 83 or the like can be suitably used.

As the pigment used for the magenta ink, C.I. I. Pigment Red 5, C.I. I. Pi
gment Red 7, C.I. I. Pigment R
ed12, C.I. I. Pigment Red 48 (C
a), C.I. I. Pigment Red 48 (M
n), C.I. I. Pigment Red 57 (C
a), C.I. I. Pigment Red 112, C.I.
I. Pigment Red 122 and the like can be preferably used.

As the pigment used for the cyan ink,
C. I. Pigment Blue 1, C.I. I. Pig
ment blue 2, C.I. I. Pigment B
lue 3, C.I. I. Pigment Blue 1
5: 3, C.I. I. Pigment Blue 16,
C. I. Pigment Blue 22, C.I. I. V
at Blue 4, C.I. I. Vat Blue 6 and the like can be preferably used. Of course, the present invention is not limited to these.

When the above-mentioned pigment is used as a coloring material, the content of the pigment is preferably 2 to 10% by weight, more preferably 3 to 8% by weight based on the total weight of the ink. is there. When the content of the pigment is less than 2% by weight, the obtained image density is too low. On the other hand, when the content of the pigment exceeds 10% by weight, it is not preferable from the viewpoint of increasing the viscosity of the ink.

The ink of the present invention contains the above-mentioned coloring materials and dithiodiglycol as essential components, and in addition to the above, the above-mentioned polyhydric alcohols and urea compounds are appropriately added. As the solvent, water or a mixture of water and an organic solvent is used. Examples of the water-soluble organic solvent used in this case include amides such as dimethylformamide and dimethylacetamide, ketones such as acetone, ethers such as tetrahydrofuran and dioxane, ethylene glycol methyl ether, diethylene glycol monomethyl ether, and triethylene. Lower alkyl ethers of polyhydric alcohols such as glycol monomethyl ether, monohydric alcohols such as ethanol, isopropyl alcohol, n-butyl alcohol, and isobutyl alcohol, glycerin, N-methyl-2-pyrrolidone,
1,3-dimethyl-imidazolidinone, triethanolamine, sulfolane, dimethyl sulfoxide and the like. The content of the water-soluble organic solvent is not particularly limited, but is generally 2 to 60% by weight of the total weight of the ink,
More preferably, 5 to 25% by weight is a suitable range.
Further, the content of water is 10 to the total weight of the ink.
About 90% by weight may be added.

In addition, the ink of the present invention further includes
If necessary, additives such as a viscosity adjusting agent, a pH adjusting agent, a preservative, various surfactants, an antioxidant and an evaporation promoter may be appropriately blended. The selection of the surfactant is particularly important in adjusting the permeability of the liquid into the recording medium.

As a preferable range of various physical properties of the ink as described above, the pH around 25 ° C. is 6 to 11.5,
More preferably 7-11, surface tension is 15-60 dyn
/ Cm, more preferably 20 to 50 dyn / cm, and the viscosity is 15 cP or less, more preferably 5 cP or less.

The ink of the present invention as described above can, of course, be used for ordinary writing implements, and it is possible to improve the sticking resistance of the ink and to obtain the effect of smooth writing. However, the ink of the present invention has a remarkable effect particularly when used for inkjet recording. An inkjet recording apparatus suitable for performing recording using the ink of the present invention will be described. In the present invention, it is preferable that a recording signal is applied to the recording ink of the recording head and droplets are ejected by the generated thermal energy. FIG. 1 shows a configuration of a recording head which is a main part of the apparatus.
This is shown in FIGS.

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

The recording ink 21 reaches the discharge orifice 22 and forms a meniscus 23 by the pressure P. Here, when an electric signal is applied to the aluminum electrodes 17-1 and 17-2, an area indicated by n of the heating head 15 generates heat rapidly, and bubbles are generated in the ink 21 in contact with the area, and the pressure is increased by the pressure. The meniscus 23 protrudes, the ink 21 is ejected to form ink droplets 24, and the ejection orifice 2
From 2, it flies toward the recording material 25. FIG. 3 shows FIG.
1 is a schematic view of a recording head in which a number of nozzles shown in FIG. The recording head is a glass plate or the like having a large number of flow paths.
And a heating head 28 similar to that described with reference to FIG. FIG. 1 is a cross-sectional view of the head 13 along the ink flow path, and FIG. 2 is a cross-sectional view taken along line AB in FIG.

FIG. 4 shows an example of an ink jet recording apparatus incorporating the 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 has a form of a wrench lever. The blade 61 is arranged at a position adjacent to the recording area of the recording head 65, and in the case of this example,
The recording head 65 is held in a protruding form in the movement path. Reference numeral 62 denotes a cap on the ejection port surface of the recording head 65, which is disposed at a home position adjacent to the blade 61, moves in a direction perpendicular to the moving direction of the recording head 65, contacts the ink ejection port surface, and performs capping. Is provided. Further, an ink absorber 63 is provided adjacent to the blade 61 and is held in a form protruding into the movement path of the recording head 65, similarly to the blade 61. The blade 61, the cap 62, and the ink absorber 63 constitute an ejection recovery unit 64, and the blade 61 and the ink absorber 63 remove moisture, dust, and the like from the ink ejection port surface.

Reference numeral 65 denotes a recording head which has discharge energy generating means and discharges ink on a recording material facing the discharge port surface where discharge ports are arranged to perform recording, and 66 denotes a recording head on which the recording head 65 is mounted. 65 is a carriage for performing the movement of 65. The carriage 66 is slidably engaged with the guide shaft 67, and a part of the carriage 66 is connected to a belt 69 driven by a motor 68 (not shown). As a result, the carriage 66 can move along the guide shaft 67, and the recording head 65 can move the recording area and the adjacent area.

Reference numeral 51 denotes a paper feed unit for inserting a recording material,
52 is 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 65, 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 ejection recovery section 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 port surface of the recording head 65, the cap 62 moves so as to protrude into the movement path of the recording head 65.

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. As a result, the ejection port surface of the recording head 65 is also wiped during this movement. The movement of the print head 65 to the home position is performed not only at the end of printing or at the time of ejection recovery, but also at the home position adjacent to the printing area at a predetermined interval while the printing head 65 moves through the printing area for printing. And the wiping is performed with this movement.

FIG. 5 is a diagram showing an example of an ink cartridge 45 containing ink supplied to the head via an ink supply member, for example, a tube. Here, reference numeral 40 denotes an ink storage portion that stores the supply ink, for example, an ink bag, and a rubber stopper 42 is provided at the tip thereof.
By inserting a needle (not shown) into the stopper 42, the ink in the ink bag 40 can be supplied to the head.
An ink absorber 44 receives the waste ink. For the ink container, the liquid contact surface with the ink is polyolefin,
Particularly, those formed of polyethylene are preferable.

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 separate as described above, and the one in which they are integrated as shown in FIG. 6 is also suitably used. .

In FIG. 6, reference numeral 70 denotes a recording unit, in which an ink storage portion for storing ink, for example, an ink absorber is stored, and a head in which the ink in the ink absorber has a plurality of orifices. The unit 71 is configured to be ejected as ink droplets. As a material of the ink absorber, for example, polyurethane can be used. Reference numeral 72 denotes an atmosphere communication port for communicating the inside of the recording unit with the atmosphere. This recording unit 70 has the configuration shown in FIG.
And is detachable from the carriage 66. In the recording apparatus used in the present invention, an ink jet recording apparatus that ejects ink droplets by applying thermal energy to ink has been described above as an example, but a piezo-type ink jet recording apparatus using a piezoelectric element may be used. Available as well.

[0064]

Next, the present invention will be specifically described with reference to examples and comparative examples, but the present invention is not limited to these examples. Example 1 After sufficiently stirring each of the components shown below, a pore size of 0.22
Pressure filtration was performed using a μm fluoropore filter (trade name, manufactured by Sumitomo Electric Industries, Ltd.) to produce an ink of Example 1. Glycerin 8% by weight Dithiodiglycol 8% by weight Isopropyl alcohol 3% by weight Dye C.I. I. Direct Blue 199 3% by weight-Pure water 78% by weight After the above ink was prepared, the obtained ink was packed in a BJC4000 cartridge, and the following evaluation was performed.

[Evaluation Items] (1) Start-up Characteristics Turn off the printer under 25 ° C., 10% RH environment.
After standing for 2 hours at room temperature and normal humidity, the power was turned on to confirm the initial printing state. The evaluation criteria are as follows. Table 1 shows the evaluation results. ◎: There is no difference from the printing state before leaving. ○: There is a slight difference from the printing state before leaving, but there is no problem in printing. ×: There is clearly a difference from the printing state before leaving.

(2) Sticking Resistance After removing the BJC4000 head from the main body at 35 ° C. and 10% RH environment and leaving it for 2 weeks, the BJC4000 head is attached to a printer and checked whether or not printing can be recovered by a normal recovery operation. Checked. The evaluation criteria are as follows. Table 1 shows the evaluation results. ◎: Recovery by main body recovery operation ○: Recovery by multiple main body recovery operations ×: No recovery by main body recovery operation

(3) Ejection Stability Using BJC4000, a character pattern was continuously printed until the end of the cartridge, and the character quality was visually evaluated. The evaluation criteria are as follows. Table 1 shows the evaluation results. ◎: There is no difference between the character quality near the beginning and end of use of the cartridge ○: There is a slight difference in the character quality near the start and end of use of the cartridge, but there is no problem in printing ×: There is a difference in the character quality near the start and end of use of the cartridge There is

Example 2 An ink containing dithiodiglycol and a polyhydric alcohol was prepared in the same manner as in Example 1 except that the components of the ink were changed to the following composition, and the same evaluation as in Example 1 was performed. Carried out. Table 1 shows the results.・ Diethylene glycol 8% by weight ・ Dithiodiglycol 8% by weight ・ Isopropyl alcohol 3% by weight ・ Dye exemplary compound 1 3% by weight ・ Pure water 78% by weight

Example 3 An ink containing dithiodiglycol, a polyhydric alcohol and urea was prepared in the same manner as in Example 1 except that the components of the ink were changed as follows. Was evaluated. Table 1 shows the results.・ Urea 5% by weight ・ Glycerin 5% by weight ・ Dithiodiglycol 5% by weight ・ Isopropyl alcohol 3% by weight ・ Dye C.I. I. Direct Black 62 3% by weight ・ Acetyleneol 1% by weight ・ Pure water 78% by weight

Example 4 An ink containing dithiodiglycol, a polyhydric alcohol and a urea compound was prepared in the same manner as in Example 1 except that the components of the ink were changed to the following composition. The same evaluation was performed. Table 1 shows the results.・ 1,1,3,3-tetramethylurea 5% by weight ・ Diethylene glycol 5% by weight ・ Dithiodiglycol 10% by weight ・ Ethyl alcohol 3% by weight ・ Dye C.I. I. Direct Blue 199 3% by weight ・ Pure water 74% by weight

Example 5 In order to prepare an ink using a coloring material as a pigment, first, a carbon black dispersion was prepared by the following method, and then the dispersion was used as an ink.・ 15% by weight of MCF88 (manufactured by Mitsubishi Kasei) ・ 5% by weight of a 15% aqueous solution of styrene acrylic acid copolymer (acid value: 120, average molecular weight: 8,000, manufactured by Seiko Chemical) (pH adjusted to about 9 with monoethanolamine)・ Pure water 60% by weight The above material is batch type vertical sand mill (made by IMEX)
, And glass beads having a diameter of 1 mm were filled as a medium, and subjected to a dispersion treatment for 3 hours while cooling with water. This dispersion was centrifuged to remove coarse particles, thereby producing a carbon black dispersion.

Next, the mixture was mixed with the following composition and thoroughly stirred.
A pigment ink of Example 5 was produced. -30% by weight of the above carbon black dispersion-8% by weight of dithiodiglycol-8% by weight of glycerin-5% by weight of isopropyl alcohol-49% by weight of pure water After preparing the above ink, it was packed in a cartridge for BJC-4000, and The same evaluation as in Example 1 was performed. Table 1 shows the results.

Example 6 A pigment ink containing dithiodiglycol and a polyhydric alcohol was prepared in the same manner as in Example 5 except that the components of the ink were changed as follows. An evaluation was performed. Table 1 shows the results.・ Carbon black dispersion 30% by weight ・ Dithiodiglycol 8% by weight ・ Polyethylene glycol 8% by weight ・ Isopropyl alcohol 5% by weight ・ Pure water 49% by weight

Example 7 A pigment ink containing dithiodiglycol, a polyhydric alcohol and urea was prepared in the same manner as in Example 5 except that the components of the ink were changed to the following compositions. A similar evaluation was performed. Table 1 shows the results.・ Carbon black dispersion 30% by weight ・ Dithiodiglycol 8% by weight ・ Urea 10% by weight ・ Polyethylene glycol 5% by weight ・ Isopropyl alcohol 5% by weight ・ Pure water 42% by weight

Example 8 A pigment ink containing dithiodiglycol, a polyhydric alcohol, and a urea compound was prepared in the same manner as in Example 5 except that the components of the ink were changed to the following compositions. The same evaluation as in Example 1 was performed. Table 1 shows the results.・ Carbon black dispersion 30% by weight ・ Glycerin 5% by weight ・ Dithiodiglycol 8% by weight ・ 1,1,3,3-tetramethylurea 10% by weight ・ Isopropyl alcohol 5% by weight ・ Acetyleneol 1% by weight ・ Pure water 41 weight%

Comparative Example 1 An ink containing no dithiodiglycol was prepared in the same manner as in Example 1 except that the components of the ink were changed as follows, and the same evaluation as in Example 1 was performed. Table 1 shows the results.・ 1,1,3,3-tetramethylurea 5% by weight ・ Diethylene glycol 5% by weight ・ Ethyl alcohol 3% by weight ・ Dye C.I. I. Direct Blue 199 3% by weight ・ Pure water 84% by weight

Comparative Example 2 A pigment ink containing no dithiodiglycol was prepared in the same manner as in Example 5 except that the components of the ink were changed as follows, and the same evaluation as in Example 1 was performed. Table 1 shows the results. -30% by weight of carbon black dispersion-15% by weight of glycerin-5% by weight of isopropyl alcohol-1% by weight of acetylenol-49% by weight of pure water

[0078]

[Table 1] Table 1: Evaluation results

[0079]

As described above, according to the present invention,
In particular, the present invention provides an ink capable of maintaining stable startup characteristics, having excellent sticking resistance, and performing stable ejection when used for ink jet recording, and an ink jet recording method using the ink.

[Brief description of the drawings]

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

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

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

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

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

FIG. 6 is a perspective view showing an example of a recording unit.

[Explanation of symbols]

 13: Head 14: Ink groove 15: Heating head 16: Protective film 17-1, 17-2: Aluminum electrode 18: Heating resistor layer 19: Heat storage layer 20: Substrate 21: Ink 22: Discharge orifice (fine hole) 23 : Meniscus 24: ink droplet 25: recording medium 26: multi-groove 27: glass plate 28: heat generating head 40: ink bag 42: stopper 44: ink absorber 45: ink cartridge 51: paper feed unit 52: paper feed roller 53: paper discharge roller 61: blade 62: cap 63: ink absorber 64: ejection recovery unit 65: recording head 66: carriage 67: guide shaft 68: motor 69: belt 70: recording unit 71: head unit 72: atmosphere communication mouth

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Norifumi Hattori 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc.

Claims (11)

[Claims] 1. An ink comprising at least a coloring material and dithiodiglycol. 2. The ink according to claim 1, further comprising a polyhydric alcohol. 3. The ink according to claim 1, further comprising a compound A represented by the following general formula. (In the above formula, R _{1 to} R ₄ each represent a hydrogen atom or an alkyl group.) 4. The ink according to claim 3, wherein the compound A is urea. 5. The ink according to claim 2, wherein the polyhydric alcohol is selected from glycerin, ethylene glycol, and diethylene glycol. 6. The ink according to claim 1, wherein the coloring material is a water-soluble dye. 7. The ink according to claim 6, wherein the water-soluble dye is a water-soluble dye having a carboxyl group. 8. The color material according to claim 1, wherein the color material is a pigment.
The ink according to any one of the above. 9. The ink according to claim 8, wherein the pigment is carbon black. 10. The ink according to claim 8, wherein the pigment is an organic pigment. 11. An ink jet recording method for recording on a recording material by discharging ink from an orifice according to a recording signal.
An ink-jet recording method, characterized by being the ink according to any one of the above.