Compositions: coating or plastic – Coating or plastic compositions – Marking
Reexamination Certificate
2000-09-14
2003-02-18
Klemanski, Helene (Department: 1755)
Compositions: coating or plastic
Coating or plastic compositions
Marking
C106S031750
Reexamination Certificate
active
06521034
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an ink, an ink set, an ink cartridge, a recording unit, a color-image recording apparatus, an image recording process, a color-image forming process, and a method for improving the density of an ink-Jet recorded image.
2. Related Background Art
Inks using carbon black which is a black colorant capable of providing prints high in optical density and excellent in fastness properties and the like have heretofore been proposed as black inks for writing utensils (fountain pens, felt-tip pens, ball-point pens, etc.) and black inks for ink-jet.
In recent years, detailed researches and developments have been made from various approaches such as composition and physical properties of inks so that good recording can be made even on plain paper such as paper for copying, paper for reporting, notepaper, letter paper, bond paper and continuous slip paper which are commonly used in offices. For example, Japanese Patent Application Laid-Open Nos. 63-152681 and 64-6074 disclose water-based pigment inks comprising carbon black and a dispersing agent. Japanese Patent Application Laid-Open No. 8-3498 has offered a technical problem that when an ink comprising carbon black together with a dispersing agent is used as an ink for ink-jet printer, ejection becomes unstable, or sufficient optical density is not achieved, and discloses a water-based pigment ink using a self-dispersing carbon black, but using no dispersing agent, as an ink capable of solving such a problem.
SUMMARY OF THE INVENTION
When printing is conducted on paper having high permeability, such as plain paper, with the conventional water-based inks, sharpness of characters printed may be impaired, or image density may be deteriorated to impair image quality in some cases In order to solve such a problem, it is considered to improve the coloring ability of inks by causing the inks not to penetrate into a recording medium as much as possible. In this case, however, another problem arises: the inks remain on the recording medium without penetrating into the recording medium, and so-called “bleeding” between different colors occurs at boundaries between them when a color image is formed.
It is therefore an object of the present invention to solve the above-described problems involved in the prior art and provide an ink, an ink set, an ink cartridge, a recording unit, a color-image recording apparatus, an image recording process and a color-image forming process which can prevent influence on image quality by the kinds of recording media, stably provide images excellent in image quality, effectively inhibit the occurrence of bleeding upon the formation of-color images and are excellent in long-term shelf stability in ink.
Another object of the present invention is to provide a water-based ink for ink- et, which can provide images extremely high in optical density, is low in dependence of the image density on recording media, has excellent stability and is hard to cause bleeding with another color ink on a recording medium when it is used in color recording.
A further object of the present invention is to provide a method for further improving the density of an image obtained by an ink-jet recording method using an ink containing a self-dispersing carbon black.
The above objects can be achieved by the present invention described below.
According to an embodiment of the present invention, there is thus provided an ink comprising at least one salt selected from the group consisting of (M
1
)
2
SO
4
, CH
3
COO(M
1
), Ph-COO(M
1
), (M
1
)NO
3
, (M
1
)Cl, (M
1
)Br, (M
1
)I, (M
1
)
2
SO
3
and (M
1
)
2
CO
3
, wherein M
1
represents an alkali metal, ammonium or organic ammonium, and Ph represents a phenyl group, and a self-dispersing anionic carbon black having a functional-group density of at least 1.8 (&mgr;mol/m
2
) on its surface.
According to another embodiment of the present invention, there is also provided an ink comprising at least one salt selected from the group consisting of (M
1
)
2
SO
4
, CH
3
COO(M
1
), Ph-COO(M
1
), (M
1
)NO
3
, (M
1
)Cl, (M
1
)Br, (M
1
)I, (M
1
)
2
SO
3
and (M
1
)
2
CO
3
, wherein M
1
represents an alkali metal, ammonium or organic ammonium, and Ph represents a phenyl group, and a self-dispersing anionic carbon black having a functional-group density of at least 0.45 (mmol/g) on its surface, the ink undergoing no substantial change in viscosity even when it is stored for one month in an environment of 60° C.
According to an embodiment of the present invention, there is further provided an ink set comprising in combination a water-based color ink comprising at least one coloring material selected from among coloring materials for cyan, magenta, yellow, red, green and blue, and the above-described ink according to the present invention.
According to an embodiment of the present invention, there is still further provided an ink cartridge comprising an ink tank which contains the above-described ink according to the present invention
According to an embodiment of the present invention, there is yet still further provided a recording unit comprising an ink container portion containing an ink-jet ink and a head portion for ejecting the ink, the ink-jet ink comprising at least one salt selected from the group consisting of (M
1
)
2
SO
4
, CH
3
COO(M
1
), Ph-COO(M
1
), (M
1
)NO
3
, (M
1
)Cl, (M
1
)Br, (M
1
)I, (M
1
)
2
SO
3
and (M
1
)
2
CO
3
, wherein M
1
represents an alkali metal, ammonium or organic ammonium, and Ph represents a phenyl group, and a self-dispersing anionic carbon black having a functional-group density of at least 1.8 (&mgr;mol/m
2
) on its surface.
According to an embodiment of the present invention, there is yet still further provided an image recording apparatus comprising an ink-jet ink and a recording head for ejecting the ink, the ink-jet ink comprising at least one salt selected from the group consisting of (M
1
)
2
SO
4
, CH
3
COO(M
1
), Ph-COO(M
1
), (M
1
)NO
3
, (M
1
)Cl, (M
1
)Br, (M
1
)I, (M
1
)
2
SO
3
and (M
1
)
2
CO
3
, wherein M
1
represents an alkali metal, ammonium or organic ammonium, and Ph represents a phenyl group, and a self-dispersing anionic carbon black having a functional-group density of at least 1.8 (&mgr;mol/m
2
) on its surface.
According to another embodiment of the present invention, there is yet still further provided a color-image recording apparatus comprising an ink container portion containing an ink-jet ink comprising at least one salt selected from the group consisting of (M
1
)
2
SO
4
, CH
3
COO(M
1
), Ph-COO(M
1
), (M
1
)NO
3
, (M
1
)Cl, (M
1
)Br, (M
1
)I, (M
1
)
2
SO
3
and (M
1
)
2
CO
3
, wherein M
1
represents an alkali metal, Ammonium or organic ammonium, and Ph represents a phenyl group, and a self-dispersing anionic carbon black having a functional-group density of at least 1.8 (&mgr;mol/m
2
) on its surface, another ink container portion containing a water-based, ink-set color ink comprising at least one coloring material selected from among coloring materials for cyan, magenta, yellow, red, green and blue, and recording head portions for respectively ejecting the inks contained in the respective ink container portions.
According to an embodiment of the present invention, there is still further provided an image recording process comprising the step of ejecting an ink-jet ink comprising at least one salt selected from the group consisting of (M
1
)
2
SO
4
, CH
3
COO(M
1
), Ph-COO(M
1
), (M
1
)NO
3
, (M
1
)Cl, (M
1
)Br, (M
1
)I, (M
1
)
2
SO
3
and (M
1
)
2
CO
3
, wherein M
1
represents an alkali metal, ammonium or organic ammonium, and Ph represents a phenyl group, and a self-dispersing anionic carbon black having a functional-group density of at least 1.8 (&mgr;mol/m
2
) on its surface toward the surface of a recording medium to apply the ink to the surface thereof, thereby recording an image.
According to an embodiment of the present invention, there is still further provided a process for forming a color image comprising the steps of ejecting a first water-b
Mishina Shinya
Osumi Koichi
Watanabe Tomonari
Faison Veronica F.
Klemanski Helene
LandOfFree
Ink, ink set, ink cartridge, recording unit, color-image... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Ink, ink set, ink cartridge, recording unit, color-image..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ink, ink set, ink cartridge, recording unit, color-image... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3116329