Title: Water base ink for ink-jet recording
Abstract: A water base ink for ink-jet recording comprises water, a coloring agent, a water-soluble organic solvent, and a benzotriazole-based metal-inactivating agent and alkanolamine. When the ink is used in an ink-jet recording apparatus which has the metal member containing nickel or nickel alloy in an ink supply passage, nickel is eluted from the metal member in an amount of not more than 50 ppm. The ink makes it possible to perform stable jetting operation for a long term without causing any deterioration of metal members of a discharge head due to the metallic corrosion and the elution of nickel into the ink.
Patent Number: 6,938,999 Issued on 09/06/2005 to Koga, et al.
| Inventors:
|
Koga; Narumi (Nagoya, JP);
Goto; Kazuma (Nagoya, JP);
Kobayashi; Naomichi (Nagoya, JP);
Aoyama; Michiko (Nagoya, JP);
Higashiyama; Shunichi (Yotsukaichi, JP);
Fujioka; Masaya (Nagoya, JP)
|
| Assignee:
|
Brother Kogyo Kabushiki Kaisha (Nagoya, JP)
|
| Appl. No.:
|
642206 |
| Filed:
|
August 18, 2003 |
Foreign Application Priority Data
| Mar 29, 2001[JP] | 2001-097014 |
| Current U.S. Class: |
347/100; 106/31.13 |
| Intern'l Class: |
G01D 011/00; C09D 011/00 |
| Field of Search: |
347/100
106/311.3,312.7,316
|
References Cited [Referenced By]
U.S. Patent Documents
| 4605939 | Aug., 1986 | Hubbard et al.
| |
| 5034058 | Jul., 1991 | Akiyama et al.
| |
| 5281262 | Jan., 1994 | Saito.
| |
| 5402159 | Mar., 1995 | Takahashi et al.
| |
| 5992982 | Nov., 1999 | Suzuki.
| |
| Foreign Patent Documents |
| A 62-1016/72 | May., 1987 | JP.
| |
| A 4-341851 | Nov., 1992 | JP.
| |
Primary Examiner: Brooke; Michael S.
Attorney, Agent or Firm: Oliff & Berridge, PLC
Parent Case Text
This is a Continuation of application Ser. No. 10/103,731 filed Mar. 25, 2002
now U.S. Pat. No. 6,648,463. The entire disclosure of the prior application is
hereby incorporated by reference herein in its entirety.
Claims
1. An ink for ink-jet recording comprising:
water;
a coloring agent;
a water-soluble organic solvent; and
at least one of a benzotriazole-based metal-inactivating agent and alkanolamine
so that the total amount of the benzotriazole-based metal-inactivating agent and
the alkanolamine is from 0.1% to 0.4% by weight of the weight of the ink.
2. The ink according to claim 1, wherein the benzotriazole-based metal-inactivating
agent is one selected from the group consisting of 1,2,3-benzotriazole, 1,2,3-benzotriazole
sodium salt, methyl-1H-benzotriazole, and methyl-1H-benzotriazoleamine salt.
3. The ink according to claim 1, wherein the alkanolamine is triethanolamine
or diethanolamine.
4. The ink according to claim 1, wherein the ink contains the benzotriazole-based
metal-inactivating agent and the alkanolamine.
5. The ink according to claim 1, further comprising glycerol.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a water base ink for ink-jet recording which
avoids any metallic corrosion and elution of nickel from metal members included
in a discharge head of an ink-jet recording apparatus and which makes it possible
to perform highly accurate printing operation.
2. Description of the Related Art
The printer technique, which is based on the ink-jet recording system, resides
in the following printing technique. That is, inks of several basic colors are
converted into minute liquid droplets of several picoliters to several tens picoliters,
and the minute liquid droplets are selectively landed on the paper so that an image
is formed thereby, for example, by means of the bubble system in which the inks
are discharged from minute nozzles by using bubbles generated by rapid heating
operation, or the piezoelectric system in which the inks are discharged from minute
nozzles by using piezoelectric elements which are deformable depending on application
of voltage.
The ink-jet recording system has advantages of high printing quality and high
printed image quality based on the control of discharge of the minute liquid droplets.
An image, which has color reproducibility close to full-color and which has no
granular texture, can be formed by highly accurately landing the minute liquid
droplets of several picoliters on the paper. However, in order to successfully
discharge the minute liquid droplets as described above, it is necessary to adapt
a highly accurate technique for controlling the landing of the minute liquid droplets
discharged from a sufficiently thin nozzle. In order to highly accurately discharge
the ink from such a nozzle having a minute diameter, it is necessary to remove
the dust and impurities from the ink. Therefore, it is necessary that the water
base ink for ink-jet recording is subjected to precise filtration after preparing
the ink. Further, it is necessary that materials, which have no compatibility with
the ink and which are sufficiently washed, are used for all parts which make contact
with the ink.
Several types of ink-jet recording apparatuses include metal members containing
nickel or nickel alloy used for their discharge heads. When the ink is water-based,
then the nickel is eluted into the ink as a result of long term contact, and metallic
corrosion takes place in some cases. As a result, a problem arises as follows.
That is, the metal member is deteriorated due to the elution of nickel and the
metallic corrosion as described above, and it is impossible to highly accurately
control the discharge and the landing operation.
SUMMARY OF THE INVENTION
The present invention has been made in order to solve the problem as described
above, an object of which is to provide a water base ink for ink-jet recording
which makes it possible to perform stable jetting operation for a long term without
causing any deterioration of metal members of a discharge head due to the metallic
corrosion and the elution of nickel into the ink and which makes it possible to
perform highly reliable and highly accurate recording.
According to a first aspect of the present invention, there is provided
an ink-jet printer comprising:
an ink-jet head which has at least a part of ink flow passage formed of nickel
or nickel alloy;
ink which contains benzotriazole-based metal-inactivating agent; and
an ink tank which accommodates the ink and which supplies the ink to the ink-jet head.
According to a second aspect of the present invention, there is provided
an ink-jet printer comprising:
an ink-jet head which has at least a part of ink flow passage formed of nickel
or nickel alloy;
ink which contains alkanolamine; and
an ink tank which accommodates the ink and which supplies the ink to the ink-jet head.
In the printer of the present invention, the ink accommodated in the ink tank
contains the benzotriazole-based metal-inactivating agent or alkanolamine. Therefore,
the elution into the ink of nickel or nickel alloy which constitutes the ink-jet
head is suppressed. Especially, it is possible to suppress the amount of elution
of nickel to be not more than 50 ppm. In this specification, the amount of elution
of nickel means the amount of elution of nickel obtained when a metal piece (surface
area: about 4.5 cm
2, weight: about 1 g) is immersed in the ink of about
20 mL followed by being left to stand for 2 weeks under conditions of temperature
of 60° C. and humidity of 40%.
According to a third aspect of the present invention, there is provided
an ink for ink-jet recording comprising:
water;
a coloring agent;
a water-soluble organic solvent; and
a benzotriazole-based metal-inactivating agent and alkanolamine. The present
invention
will be described in detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a perspective view illustrating an embodiment of a color ink-jet
printer as an ink-jet recording apparatus of the present invention.
FIG. 2 shows a perspective view illustrating a head unit as viewed from the
side of nozzles.
FIG. 3 shows an exploded perspective view illustrating parts of the head unit.
FIG. 4 shows an exploded perspective view illustrating parts of the head unit,
in which the color ink-jet printer is viewed from a position thereover.
FIG. 5 shows a bottom view illustrating the head unit.
FIG. 6 shows a perspective view illustrating respective parts of a piezoelectric
ink-jet head.
FIG. 7 shows a sectional view illustrating the piezoelectric ink-jet head.
FIG. 8 shows an exploded perspective view illustrating a cavity plate.
FIG. 9 shows a magnified exploded perspective view illustrating the cavity plate.
FIG. 10 shows a magnified exploded perspective view illustrating a piezoelectric actuator.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As for the water base ink for ink-jet recording of the present invention, nickel
is eluted from a metal member in an amount of not more than the certain amount
when the water base ink for ink-jet recording is applied to an ink-jet recording
apparatus which has the metal member containing nickel or nickel alloy in at least
an ink supply passage to a discharge section for forming an image on paper by discharging
fine and minute liquid droplets from a pore or small hole.
FIG. 1 shows a perspective view illustrating an embodiment of a color ink-jet
printer as a ink-jet recording apparatus of the present invention. With reference
to FIG. 1, the color ink-jet printer
100 comprises ink cartridges
61
which are filled with, for example, four color inks of cyan, magenta, yellow, and
black respectively, a head unit
63 which is provided with a piezoelectric
ink-jet head
6 for performing the printing on the printing paper
62,
a carriage
64 which carries the ink cartridges
61 and the head unit
63 thereon, a drive unit
65 which reciprocates the carriage
64
in the linear direction, a platen roller
66 which extends in the direction
of reciprocating movement of the carriage
64 and which is arranged opposingly
to the piezoelectric ink-jet head
6, and a purge unit
67.
The drive unit
65 comprises a carriage shaft
71 which is arranged
at the lower end of the carriage
64 and which extends in parallel to the
platen roller
66, a guide
72 which is arranged at the upper end of
the carriage
64 and which extends in parallel to the carriage shaft
71,
two pulleys
73,
74 which are disposed between the carriage shaft
71 and the guide
72 and which are arranged at both ends of the carriage
shaft
71, and an endless belt
75 which extends across the pulleys
73,
74. A part of the endless belt
75 is joined to the back
surface of the carriage
64.
When the first pulley
73 is rotated in accordance with the driving motion
of a motor
76, the carriage
64, which is joined to the endless belt
75, is moved linearly along the carriage shaft
71 and the guide
72
in accordance with the rotation of the pulley
73.
The printing paper
62 is fed from an unillustrated paper feed cassette
which is provided on the side of the ink-jet printer
100. The printing paper
is introduced into the space between the piezoelectric ink-jet head
6 and
the platen roller
66. Predetermined printing is performed on the printing
paper with the ink discharged from the piezoelectric ink-jet head
6. After
that, the printing paper is discharged. The paper feed mechanism and the paper
discharge mechanism for the printing paper
62 are omitted from the illustration
in FIG.
1.
The purge unit
67 is provided on the side of the platen roller
66.
The purge unit
67 is arranged so that the purge unit
67 is opposed
to the piezoelectric ink-jet head
6 when the head unit
63 is disposed
at the reset position. The purge unit
67 is provided with caps
81
which abut against open surfaces of nozzles to cover the plurality of nozzles of
the piezoelectric ink-jet head
6 as described later on, a pump
82,
a cam
83, and an ink storage unit
84. When the head unit
63
is at the reset position, then the nozzles of the piezoelectric ink-jet head
6
are covered with the caps
81, and the ink including bubbles or the like,
which remains in the piezoelectric ink-jet head
6, is aspirated by the pump
82 in accordance with the driving motion of the cam
83 in order to
recover the piezoelectric ink-jet head
6 thereby. Accordingly, it is possible
to avoid any discharge failure or the like which would be otherwise caused, for
example, by the growth of bubbles and the retention of the ink when the ink is
introduced at the initial stage. The aspirated defective ink is stored in the ink
storage unit
84.
FIGS. 2,
3, and
4 show perspective views of the head unit
63.
FIG. 5 shows a bottom view of the head unit
63.
As shown in FIG. 4, the head unit
63, which is carried on the carriage
64 that runs along the printing paper
62, is formed to have a substantially
box-shaped configuration with its open upper surface. The head unit
63 has
a carrying section
3 to which the four ink cartridges
61 can be detachably
installed from positions thereover. Ink supply passages
4a,
4b,
4c,
4d, which are connectable to ink discharge sections
(not shown) of the respective ink cartridges
61, make communication up to
the lower surface of the bottom plate
5 of the head unit
63 on the
first side
3a of the carrying section
3. A packing made of
rubber or the like (not shown), which is designed to make tight contact with each
of the ink discharge sections (not shown) of the respective ink cartridges
61,
is arranged on the upper surface on the first side
3a of the carrying
section
3.
The bottom plate
5 is formed horizontally to protrude at a position stepped
downwardly from the carrying section
3. As shown in FIGS. 3 and 5, two support
sections
8, which are provided to arrange the two piezoelectric ink-jet
heads
6 in parallel, are formed in a stepped configuration on the lower
surface side of the bottom plate
5. A plurality of hollow portions
9a,
9b are formed to vertically penetrate through the respective support
sections
8 in order to make fixation with a UV-curable adhesive.
FIG. 6 shows a perspective view illustrating the piezoelectric ink-jet head
6. FIG. 7 shows a sectional view illustrating the piezoelectric ink-jet
head
6. As shown in FIG. 6, the piezoelectric ink-jet head
6 comprises
a stacked type cavity plate
10, a plate type piezoelectric actuator
20
which is bonded and stacked onto the cavity plate
10 with an adhesive or
an adhesive sheet (not shown), and a flexible flat cable
40 which is superimposed
and joined onto the upper surface of the plate type piezoelectric actuator
20
in order to make electric connection with respect to external equipment. The ink,
which is supplied from the ink cartridge
61, is discharged downwardly (in
the downward direction in FIG. 6) from the nozzles opened on the lower surface
side (lower side in FIG. 6) through supply ports
19a provided on
the upper surface side (upper side in FIG. 6) of the cavity plate
10.
FIG. 8 shows an exploded perspective view illustrating the cavity plate
10.
FIG. 9 shows a magnified exploded perspective view illustrating the cavity plate
10. The cavity plate
10 has a structure comprising five thin metal
plates of a nozzle plate
11, two manifold plates
12,
12′,
a spacer plate
13, and a base plate
14 which are superimposed, joined,
and stacked with an adhesive respectively. In this embodiment, each of the plates
11 to
14 is made of 42% nickel alloy steel plate (
42 alloy)
with a thickness of about 50 to 150 μm.
As shown in FIG. 9, a plurality of pressure chambers
16, which are slender
and which extend in a direction perpendicular to the longitudinal direction of
the base plate
14, are bored in two rows in a zigzag arrangement through
the base plate
14. Throttle sections
16d connected to the
respective pressure chambers
16 and ink supply holes
16b connected
to the throttle sections
16d are formed in a recessed form on the
base plate
14 on the side of the spacer plate
13. The respective
ink supply holes
16b are communicated with a common ink chamber
12a
in the manifold plate
12′ via respective ink supply holes
18
which are bored through both right and left side portions of the spacer plate
13.
First ends
16a of the respective pressure chambers
16
are communicated with the nozzles
15 which are arranged in a zigzag arrangement
in the nozzle plate
11, via through-holes
17 each having a minute
diameter bored in a zigzag arrangement as well through the spacer plate
13
and the two manifold plates
12,
12′.
As shown in FIG. 8, the two ink supply holes
19a,
19b,
which are provided to supply the ink from the common ink cartridge to the two common
ink chambers
12a in the manifold plate
12′, are bored
through each of the base plate
14 and the spacer plate
13.
As shown in FIG. 8, the two common ink chambers
12a,
12b
are provided for each of the two manifold plates
12,
12′
with the row of the plurality of nozzles
15 of the nozzle plate
11
intervening therebetween. The common ink chambers
12a,
12b
extend over a long distance in parallel to the row of the nozzles. The common
ink chambers
12a,
12b are located in the planes parallel
to the plane formed by the plurality of pressure chambers
16 in the base
plate
14. Further, the common ink chambers
12a,
12b
are positioned on the side of the open surface of the plurality of nozzles
15 on the nozzle plate
11 as compared with the plurality of pressure
chambers
16.
The ends of the common ink chambers
12a,
12b are
bent toward the center in order to make communication, for example, with the ink
supply holes
19a,
19b. In this structure, the upper
surfaces of the upper common ink chambers
12a are tightly closed
by the spacer plate
13 stacked on the manifold plate
12′.
The lower common ink chambers
12b are formed in a recessed form on
the manifold plate
12 with their closed bottom surfaces.
In this structure, the common ink chambers
12a,
12b are
tightly closed by the nozzle plate
11 and the spacer plate
13 stacked
on the two manifold plates
12. The plurality of ink discharge nozzles
15
each having a minute diameter (for example, about 25 μm) are bored in two
rows through the nozzle plate
11 in the longitudinal direction of the nozzle
plate
11.
The cavity plate
10 is constructed as described above. Accordingly, the
ink, which flows into the common ink chambers
12a,
12b
from the ink supply holes
19a,
19b bored through
the first end portions of the base plate
14 and the spacer plate
13,
passes from the common ink chambers
12a through the respective ink
supply holes
18, the respective ink supply holes
16b, and
the throttle sections
16d, and the ink is distributed to the respective
pressure chambers
16. The ink flows in the direction toward the first ends
16a of the respective pressure chambers
16. The ink passes
through the respective through-holes
17, and the ink arrives at the nozzles
15 corresponding to the respective pressure chambers
16.
FIG. 10 shows a magnified exploded perspective view illustrating the piezoelectric
actuator
20. As shown in FIG. 10, the piezoelectric actuator
20 has
a structure in which two piezoelectric sheets
21,
22 and one insulating
sheet
23 are stacked. A plurality of driving electrodes
24, which
have a line width corresponding to each of the pressure chambers
16 of the
cavity plate
10, are provided in a zigzag arrangement on the upper surface
of the piezoelectric sheet
21 disposed at the lowermost layer. First ends
24a of the respective driving electrodes
24 are formed so
that they are exposed to the right and left side surfaces
20c perpendicular
to the front and back surfaces
20a,
20b of the piezoelectric
actuator
20.
A common electrode
25, which is common to the plurality of pressure chambers
16, is provided on the upper surface of the piezoelectric sheet
22
disposed at the next layer. First ends
25a of the common electrode
25 are also formed so that they are exposed to the right and left side surfaces
20c in the same manner as the first ends
24a of the
respective driving electrodes
24. Respective areas in the piezoelectric
sheet
22, which are interposed between the respective driving electrodes
24 and the common electrode
25, serve as pressure-producing parts
corresponding to the respective pressure chambers
16.
Surface electrodes
26 corresponding to the respective driving electrodes
24 and surface electrodes
27 corresponding to the common electrode
25 are provided on the upper surface of the insulating sheet
23 disposed
at the uppermost layer so that they are aligned along the right and left side surfaces
20c.
First recessed grooves
30 disposed at the first ends
24a of
the respective driving electrodes
24 and second recessed grooves
31
disposed at the first ends
25a of the common electrode
25
are provided on the right and left side surfaces
20c so that they
extend in the stacking direction respectively. As shown in FIG. 7, side surface
electrodes
32, which electrically connect the respective driving electrodes
24 and the respective surface electrodes
26, are formed in the respective
first recessed grooves
30. Side surface electrodes
33, which electrically
connect the common electrode
25 and the surface electrodes
27, are
formed in the second recessed grooves
31. Electrodes of reference numerals
of
28,
29 are electrodes of extra pattern.
The cavity plate
10 and the piezoelectric actuator
20, which are
constructed as described above, are stacked so that the respective pressure chambers
16 of the cavity plate
10 correspond to the driving electrodes
24
of the piezoelectric actuator
20. The flexible flat cable
40 is superimposed
and pressed on the upper surface
20a of the piezoelectric actuator
20. Accordingly, various wiring patterns (not shown) of the flexible flat
cable
40 are electrically joined to the respective surface electrodes
26,
27.
In the ink-jet printer constructed as described above, the printing paper
62
is fed from the unillustrated paper feed cassette. When the printing paper
62
is introduced into the space between the piezoelectric ink-jet head
6 and
the platen roller
66, the carriage
64 is moved from the reset position
to a predetermined position along the guide plate
72 in accordance with
the driving motion of the motor
76.
When a voltage is applied between the common electrode
25 and an arbitrary
driving electrode
24 of the respective driving electrodes
24 of the
piezoelectric actuator
20 of the piezoelectric ink-jet head
6, a
certain strain is generated in the stacking direction by the piezoelectric action
at a portion of the driving electrode
24 of the piezoelectric sheet
22
to which the voltage is applied, i.e., at the pressure-producing part. The internal
volume of the pressure chamber
16 corresponding to each of the driving electrodes
24 is decreased by the pressure caused by the strain. Accordingly, the ink
in the pressure chamber
16 is discharged in a droplet form from the nozzle
15, and the predetermined printing operation is performed on the printing
paper
62. Thus, the printing operation is advanced on the printing paper
62 while making the reciprocating movement of the carriage
64 in
the linear direction along the guide plate
72. When the printing operation
is completed, the head unit
63, which is carried on the carriage
64,
is returned to the reset position. The plurality of nozzles
15 of the piezoelectric
ink-jet head
6 are covered with the caps
81.
As for the water base ink for ink-jet recording of the present invention, the
amount of elution of nickel from the metal members which compose the piezoelectric
ink-jet head
6 and the ink flow passage is not more than 50 ppm. If the
elution amount exceeds 50 ppm, then the metal member is deteriorated due to the
metallic corrosion, and it is impossible to highly accurately control the discharge landing.
The water base ink for ink-jet recording as described above includes those containing
water, a water-soluble organic solvent, and a coloring agent which is capable of
being dispersed or dissolved in water, and further containing a benzotriazole-based
metal-inactivating agent and/or alkanolamine.
The water is not specifically limited. However, it is preferable to use deionized
water or pure water. It is preferable that the content of water is not less than
40% by weight with respect to the total weight of the ink. If the content is less
than 40% by weight, it is difficult that the viscosity of the ink in the ordinary
state is maintained to be a low viscosity at which the ink can be normally jetted.
The water-soluble organic solvent is principally used in order to avoid the dry-up
and the occurrence of deposition from the ink at the forward end of the ink-jet
head. Therefore, it is preferable to use solvents having low volatility and high
solubility for dye, including, for example, polyalkylene glycol such as polyethylene
glycol; alkylene glycol such as ethylene glycol, propylene glycol, butylene glycol,
diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol,
1,2,6-hexanetriol, thiodiglycol, 1,3-butanediol, 1,5-pentanediol, and hexylene
glycol; glycerol; and pyrrolidone such as 2-pyrrolidone and N-methyl-2-pyrrolidone.
The water-soluble organic solvent as described above may be used singly. Alternatively,
two or more of the water-soluble organic solvents may be used in combination.
It is preferable that the content of the water-soluble organic solvent is 5 to
40% by weight with respect to the total amount of the ink. If the content is less
than 5% by weight, then the moistening function is insufficient, and problems such
as deposition and dry-up arise in some cases. On the other hand, if the content
exceeds 40% by weight, then the viscosity of the ink is unnecessarily increased,
and problems arise in some cases such that the ink cannot be discharged and the
ink is dried extremely slowly on the recording paper. The content is more preferably
7 to 40% by weight, and much more preferably 10 to 30% by weight.
Those usable as the coloring agent include, for example, dyes and pigments.
Those preferably usable as the dye include, for example, cationic and anionic dyes
such as basic dye, acidic dye, direct dye, and reactive dye. The dye as described
above is not specifically limited, including, for example, Color Index Numbers
of Basic Red 1, 1:1, 2, 12, 13, 14, 18, 22, 27, 28, 29, 34, 38, 39, 46, 46:1, 67,
69, 70; Color Index Numbers of Basic Violet 1, 2, 3, 4, 5, 7, 8, 10, 11, 11:1,
20, 33; Color Index Numbers of Basic Blue 3, 6, 7, 9, 11, 12, 16, 17, 24, 26, 41,
47, 66; Color Index Numbers of Basic Green 1, 4, 5; Color Index Numbers of Basic
Yellow 1, 11, 19, 21, 24, 25, 28, 29, 36, 45, 51, 67, 73; Color Index Numbers of
Basic Orange 14, 21, 22, 32; Color Index Numbers of Basic Brown 1, 4; Color Index
Numbers of Direct Black 17, 19, 32, 51, 71, 108, 146, 154, 168; Color Index Numbers
of Direct Blue 6, 22, 25, 71, 86, 90, 106, 199; Color Index Numbers of Direct Red
1, 4, 17, 28, 83, 227; Color Index Numbers of Direct Yellow 12, 24, 26, 86, 98,
132, 142; Color Index Numbers of Direct Orange 34, 39, 44, 46, 60; Color Index
Numbers of Direct Violet 47, 48; Color Index Number of Direct Brown 109; Color
Index Number of Direct Green 59; Color Index Numbers of Acid Black 2, 7, 24, 26,
31, 52, 63, 112, 118; Color Index Numbers of Acid Blue 9, 22, 40, 59, 93, 102,
104, 113, 117, 120, 167, 229, 234; Color Index Numbers of Acid Red 1, 6, 32, 37,
51, 52, 80, 85, 87, 92, 94, 115, 181, 256, 289, 315, 317; Color Index Numbers of
Acid Yellow 11, 17, 23, 25, 29, 42, 61, 71; Color Index Numbers of Acid Orange
7, 19; Color Index Number of Acid Violet 49; Color Index Numbers of Food Black
1, 2; and Color Index Number of Reactive Red 180.
Those usable as the pigment include many inorganic and organic pigments as
well as carbon black. The pigment is not specifically limited provided that the
pigment is capable of being dispersed in the aqueous phase. The pigment includes,
for example, azo pigment such as azo lake pigment, insoluble azo pigment, condensed
azo pigment, and chelate azo pigment; polycyclic pigment such as phthalocyanine
pigment, perylene, perynone pigment, anthraquinone pigment, quinacridone pigment,
dioxazine pigment, thioindigo pigment, isoindolinone pigment, and quinophthalone
pigment; dye lake such as basic dye type lake and acidic dye type lake; organic
pigment such as nitro pigment, nitroso pigment, and aniline black daylight fluorescent
pigment; and inorganic pigment such as titanium oxide, iron oxide-based pigment,
and carbon black-based pigment. For example, those obtained by applying a surface
treatment to the various pigments described above, for example, with a surfactant
or a macromolecular dispersing agent can be also used as the pigment. Such a material
includes, for example, graft carbon.
When the pigment as described above is used as the coloring agent, a dispersing
treatment is performed in accordance with a conventionally known method together
with an appropriate dispersing agent, a solvent, pure water, and optionally other additives.
Those usable as the dispersing agent include, for example, a surfactant and
a macromolecular dispersing agent to be used to disperse the pigment as described
in Japanese Patent Application Laid-Open No. 62-101672.
The macromolecular dispersing agent is not specifically limited, including, for
example, protein such as gelatin and albumin; natural rubber such as gum arabic
and gum traganth; glucoside such as saponin; cellulose derivative such as methyl
cellulose, carboxy cellulose, and hydroxymethyl cellulose; natural macromolecule
such as lignosulfonate and shellac; anionic macromolecule such as salt of polyacrylic
acid, salt of styrene-acrylic acid copolymer, salt of vinylnaphthalene-acrylic
acid copolymer, salt of styrene-maleic acid copolymer, salt of vinylnaphthalene-maleic
acid copolymer, and sodium salt and phosphoric acid salt of β-naphthalenesulfonic
acid-formalin condensate; and nonionic macromolecule such as polyvinyl alcohol,
polyvinyl pyrrolidone, and polyethylene glycol.
The surfactant includes, for example, anionic surfactant such as higher alcohol
sulfuric acid ester salt, liquid fatty oil sulfuric acid ester salt, and alkylarylsulfonic
acid salt; and nonionic surfactant such as polyoxyethylene alky ether, polyoxyethylene
alkyl ester, sorbitan alkyl ester, and polyoxyethylene sorbitan alkyl ester. The
dispersing agent may be used singly, or two or more of the dispersing agents may
be used in combination.
It is preferable that the dispersing agent is generally blended in an amount
of
0.01 to 20% by weight with respect to the total amount of the ink. If the blending
amount is less than 0.01% by weight, or if the blending amount exceeds 20% by weight,
then the dispersion stability of the pigment is insufficient, sometimes resulting
in destruction of dispersion such as aggregation and sedimentation of the pigment.
The dispersing machine, which is used for the dispersing treatment for the pigment
as described above, is not specifically limited. It is possible to widely use general
dispersing machines. However, the dispersing machine includes, for example, ball
mills, roll mills, and sand mills. Especially, it is preferable to use a high speed
type sand mill.
The dye and the pigment may be used singly respectively. Alternatively, two or
more dyes, two or more pigments, or two or more dyes and pigments may be mixed
and used. It is preferable that the blending amount of the coloring agent is generally
0.1 to 20% by weight with respect to the total weight of the ink. If the blending
amount is less than 0.1% by weight, it is difficult to obtain a sufficient printing
density. If the blending amount exceeds 20% by weight, then the dye fails to be
sufficiently dissolved in the solvent resulting in deposition in some cases, and
the pigment hardly maintains the dispersion stability. The blending amount is more
preferably 0.3 to 1.5% by weight, and much more preferably 0.5 to 10% by weight.
The present inventors have found out that the elution of nickel from the metal
member of the discharge head and the metallic corrosion accompanied thereby can
be suppressed by adding the benzotriazole-based metal-inactivating agent and/or
alkanolamine to the ink. It is considered that the benzotriazole-based metal-inactivating
agent and alkanolamine form a dense synthetic coating on the metal surface, and
the coating functions as a protective film against corrosion to suppress the corrosion.
It is preferred that both of a benzotriazole-based metal-inactivating agent and/or
alkanolamine are added to the ink.
The benzotriazole-based metal-inactivating agent is not specifically limited
provided that the agent functions as described above. The benzotriazole-based metal-inactivating
agent includes, for example, compounds having the benzotriazole skeleton such as
1,2,3-benzotriazole, 1,2,3-benzotriazole sodium salt, methyl-1H-benzotriazole,
methyl-1H-benzotriazoleamine salt, 2-(2′-hydroxy-5′-methylphenyl)benzotriazole,
and 1-(N,N-bis(2-ethylhexyl)aminomethyl)benzotriazole.
The alkanolamine is not specifically limited provided that it functions as described
above. The alkanolamine includes, for example, ethanolamine, diethanolamine, and triethanolamine.
A sufficient effect can be obtained even when each of the benzotriazole-based
metal-inactivating
agent and alkanolamine is used singly. However, when two or more species of the
benzotriazole-based metal-inactivating agent and alkanolamine are used in mixture,
it is possible to expect a higher effect.
It is preferable that the content of the benzotriazole-based metal-inactivating
agent or alkanolamine is 0.01 to 5% by weight with respect to the total amount
of the ink. If the content is less than 0.01% by weight, it is impossible to obtain
any sufficient suppressing power against the metallic corrosion. If the content
exceeds 5% by weight, then the benzotriazole-based metal-inactivating agent fails
to be sufficiently dissolved in the solvent resulting in deposition in some cases,
and the alkanolamine causes strong alkaline pH of the ink resulting in occurrence
of corrosion ironically. The content is more preferably 0.05 to 3% by weight, and
much more preferably 0.1 to 1% by weight. Especially preferably, the content is
0.1 to 0.4% by weight.
Additionally, the ink of the present invention may optionally contain,
for example, hitherto known various types of penetrating agents, resin binders,
dispersing agents, surfactants, viscosity-adjusting agents, surface tension-adjusting
agents, pH-adjusting agents, dye-dissolving agents, antiseptic agents, and fungicides.
Those preferably used as the penetrating agent include polyhydric alcohol monoalkyl
ether having low odor with low vapor pressure. Those preferably used as the polyhydric
alcohol monoalkyl ether are those with which the quick-drying property of the ink
on the paper is improved by effectively quicken the penetration speed of the ink
into the recording paper to avoid the bleeding (blur at the boundary between different
colors) resulting from the slow-drying property on the recording paper, and the
feathering (moustache or whiskers-like blur along fibers of paper) is scarcely
caused by the penetration.
The polyhydric alcohol monoalkyl ether includes, for example, diethylene glycol
monomethyl ether, diethylene glycol monobutyl ether, diethylene glycol monoisobutyl
ether, dipropylene glycol monomethyl ether, dipropylene glycol monopropyl ether,
dipropylene glycol monoisopropyl ether, dipropylene glycol monobutyl ether, triethylene
glycol monomethyl ether, triethylene glycol monobutyl ether, tripropylene glycol
monomethyl ether, and tripropylene glycol monobutyl ether.
It is preferable that the content of the polyhydric alcohol monoalkyl ether is
3 to 15% by weight with respect to the total amount of the ink. If the content
is less than 3% by weight, then the penetration speed of the ink into the recording
paper is slow, and any problem arises in the drying time and the blur in some cases.
If the content exceeds 15% by weight, the penetration of the ink into the recording
paper is too quick. As a result, the ink arrives at the back of the recording paper
in some cases, or any problem arises in the blur in other cases.
Monohydric alcohol such as ethanol and isopropyl alcohol can be also used
for the water base ink for ink-jet recording of the present invention in order
to control the penetration of the ink into the recording paper and the drying performance
of the ink.
When the water base ink for ink-jet recording of the present invention is applied
to the ink-jet system of the type in which the ink is discharged in accordance
with the action of the thermal energy, for example, it is also preferable to adjust
values of thermal physical properties including, for example, the specific heat,
the coefficient of thermal expansion, and the coefficient of thermal conductivity.
The problem involved in the conventional technique is sufficiently solved in
the water base ink for ink-jet recording of the present invention obtained as described
above. The elution of nickel is not caused from the metal member disposed in the
ink supply passage, and it is possible to suppress the metallic corrosion accompanied
thereby as well.
The present invention will be explained in further detail below as exemplified
by embodiments. However, the present invention is not limited to only the embodiments.
EXAMPLES 1 TO 9 AND COMPARATIVE EXAMPLES 1 TO 9
Compositions of inks prepared in Examples 1 to 9 and Comparative Examples
1 to 9 respectively are shown in Tables 1 to 18.
| |
TABLE 1 |
| |
| |
Ink composition of Example 1 |
% by weight |
| |
| |
| |
C. I. Food Black 2 |
8 |
| |
Glycerol |
15 |
| |
Triethylene glycol-n-butyl ether |
8 |
| |
1,2,3-Benzotriazole |
0.2 |
| |
Pure water |
68.8 |
| |
| |
TABLE 2 |
| |
| |
Ink composition of Example 2 |
% by weight |
| |
| |
| |
C. I. Direct Black 154 |
6 |
| |
Glycerol |
18 |
| |
Triethylene glycol-n-butyl ether |
8 |
| |
Triethanolamine |
0.1 |
| |
Pure water |
67.9 |
| |
| |
TABLE 3 |
| |
| |
Ink composition of Example 3 |
% by weight |
| |
| |
| |
C. I. Food Black 2 |
8 |
| |
Glycerol |
6 |
| |
Diethylene glycol |
10 |
| |
Triethylene glycol-n-butyl ether |
8 |
| |
Methyl-1H-benzotriazoleamine salt |
0.2 |
| |
Pure water |
67.8 |
| |
| |
TABLE 4 |
| |
| |
Ink composition of Example 4 |
% by weight |
| |
| |
| |
C. I. Food Black 2 |
2 |
| |
C. I. Direct Black 154 |
5 |
| |
Glycerol |
6 |
| |
Diethylene glycol |
10 |
| |
Triethylene glycol-n-butyl ether |
8 |
| |
1,2,3-Benzotriazole sodium salt |
0.2 |
| |
Diethanolamine |
0.2 |
| |
Pure water |
68.6 |
| |
| |
TABLE 5 |
| |
| |
Ink composition of Example 5 |
% by weight |
| |
| |
| |
C. I. Food Black 2 |
3 |
| |
C. I. Direct Black 154 |
4 |
| |
Glycerol |
6 |
| |
Diethylene glycol |
10 |
| |
Triethylene glycol-n-butyl ether |
8 |
| |
Methyl-1H-benzotriazole |
0.2 |
| |
Triethanolamine |
0.1 |
| |
Pure water |
68.7 |
| |
| |
TABLE 6 |
| |
| |
Ink composition of Example 6 |
% by weight |
| |
| |
| |
C. I. Direct Yellow 132 |
3 |
| |
Glycerol |
28 |
| |
Triethylene glycol-n-butyl ether |
8 |
| |
Metyl-1H-benzotriazole |
0.1 |
| |
Diethanolamine |
0.1 |
| |
Pure water |
60.8 |
| |
| |
TABLE 7 |
| |
| |
Ink composition of Example 7 |
% by weight |
| |
| |
| |
C. I. Acid Red 52 |
1 |
| |
C. I. Acid Red 289 |
1.2 |
| |
Glycerol |
28 |
| |
Triethylene glycol-n-butyl ether |
8 |
| |
1,2,3-Benzotriazole |
0.1 |
| |
Pure water |
61.7 |
| |
| |
TABLE 8 |
| |
| |
Ink composition of Example 8 |
% by weight |
| |
| |
| |
C. I. Direct Blue 199 |
2.5 |
| |
Glycerol |
28 |
| |
Diethylene glycol-n-butyl ether |
6 |
| |
Triethanolamine |
0.2 |
| |
Pure water |
63.3 |
| |
| |
TABLE 9 |
| |
| |
Ink composition of Example 9 |
% by weight |
| |
| |
| |
CABOJET 300 (produced by Cabot) |
27 |
(*note) |
| |
Glycerol |
5 |
| |
Diethylene glycol |
10 |
| |
Triethylene glycol-n-butyl ether |
5 |
| |
1,2,3-Benzotriazole |
0.2 |
| |
Triethanolamine |
0.2 |
| |
Pure water |
52.6 |
| |
| |
*Note: carbon black-dispersed material having pigment content of 15% by weight
and water content of 85% by weight. |
| |
TABLE 10 |
| |
| |
Ink composition of Comparative Example 1 |
% by weight |
| |
| |
| |
C. I. Food Black 2 |
8 |
| |
Glycerol |
15 |
| |
Triethylene glycol-n-butyl ether |
8 |
| |
Pure water |
69 |
| |
| |
TABLE 11 |
| |
| |
Ink composition of Comparative Example 2 |
% by weight |
| |
| |
| |
C. I. Direct Black 154 |
6 |
| |
Glycerol |
18 |
| |
Triethylene glycol-n-butyl ether |
8 |
| |
Pure water |
68 |
| |
| |
TABLE 12 |
| |
| |
Ink composition of Comparative Example 3 |
% by weight |
| |
| |
| |
C. I. Food Black 2 |
8 |
| |
Glycerol |
6 |
| |
Diethylene glycol |
10 |
| |
Triethylene glycol-n-butyl ether |
8 |
| |
Pure water |
68 |
| |
| |
TABLE 13 |
| |
| |
Ink composition of Comparative Example 4 |
% by weight |
| |
| |
| |
C. I. Food Black 2 |
2 |
| |
C. I. Direct Black 154 |
5 |
| |
Glycerol |
6 |
| |
Diethylene glycol |
10 |
| |
Triethylene glycol-n-butyl ether |
8 |
| |
Pure water |
69 |
| |
| |
TABLE 14 |
| |
| |
Ink composition of Comparative Example 5 |
% by weight |
| |
| |
| |
C. I. Food Black 2 |
3 |
| |
C. I. Direct Black 154 |
4 |
| |
Glycerol |
6 |
| |
Diethylene glycol |
10 |
| |
Triethylene glycol-n-butyl ether |
8 |
| |
Pure water |
69 |
| |
| |
TABLE 15 |
| |
| |
Ink composition of Comparative Example 6 |
% by weight |
| |
| |
| |
C. I. Direct Yellow 132 |
3 |
| |
Glycerol |
28 |
| |
Triethylene glycol-n-butyl ether |
8 |
| |
Pure water |
61 |
| |
| |
TABLE 16 |
| |
| |
Ink composition of Comparative Example 7 |
% by weight |
| |
| |
| |
C. I. Acid Red 52 |
1 |
| |
C. I. Acid Red 289 |
1.2 |
| |
Glycerol |
28 |
| |
Triethylene glycol-n-butyl ether |
8 |
| |
Pure water |
61.8 |
| |
| |
TABLE 17 |
| |
| |
Ink composition of Comparative Example 8 |
% by weight |
| |
| |
| |
C. I. Direct Blue 199 |
2.5 |
| |
Glycerol |
28 |
| |
Diethylene glycol-n-butyl ether |
6 |
| |
Pure water |
63.5 |
| |
