Incremental printing of symbolic information – Ink jet – Fluid or fluid source handling means
Reexamination Certificate
2002-03-15
2003-02-25
Barlow, John (Department: 2853)
Incremental printing of symbolic information
Ink jet
Fluid or fluid source handling means
C347S100000
Reexamination Certificate
active
06523947
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a recording ink set which is used for an ink-jet printer and includes a combination of different color inks.
2. Description of the Related Art
The ink discharge system, which has been hitherto known for the ink-jet recording system, includes, for example, the electrostatic attraction system, the system in which mechanical vibration or displacement is applied to the ink by using a piezoelectric element or the like, and the method in which bubbles are generated by heating the ink to utilize the pressure generated thereby. Ink droplets are formed by means of the discharge system as described above, and all or a part of the droplets are adhered to a recording objective such as paper to perform the recording. Those known and used as the ink to be employed for the ink-jet recording system as described above include those in which a variety of water-soluble dyes or pigments are dissolved or dispersed in liquid media each comprising water or a combination of water and water-soluble organic solvent.
In order to adequately perform the recording for a long period of time by using the ink as described above, for example, the following conditions are required. That is, the characteristic values including, for example, the viscosity, the surface tension, the electric conductivity, and the density of the ink to be used are appropriate values. In order to avoid any clog-up at the nozzle or the orifice of the recording apparatus, no deposited matter is generated and no physical property value is changed by the influence of heat or the like. Further, the recorded image is excellent, for example, in water resistance and light resistance. A large number of suggestions have been made in order to satisfy the conditions as described above.
However, in recent years, it is more demanded to perform the recording on the regular paper rather than on the exclusive ink-jet paper in view of the cost and the consideration of the environment. In the case of most of the conventional inks, when the recording is performed on the regular paper, the color bleed is apt to occur, which is caused such that the inks of different colors are mixed with each other at portions at which the different colors are adjacent to one another. As a result, a problem arises in that the printing quality is deteriorated.
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 set comprising recording inks with which the color bleed is reduced even when the recording is performed on the regular paper.
According to a first aspect of the present invention, there is provided an ink set for ink-jet recording having a combination of inks of different colors, comprising:
a first ink which contains water, a first coloring agent, and a water-soluble organic solvent; and
a second ink which contains water, a second coloring agent different from the first coloring agent, and a water-soluble organic solvent, wherein:
a solubility parameter &dgr;1 of the water-soluble organic solvent contained in the first ink satisfies a relationship of 4≦|&dgr;1−&dgr;2| with respect to a solubility parameter &dgr;2 of the water-soluble organic solvent contained in the second ink.
In general, the bleeding, which is caused at the boundary between inks such as black and yellow, is relatively conspicuous. In the ink set of the present invention, in order to avoid the bleeding as described above, it is desirable that the first ink is a black ink containing a black coloring agent, and the second ink is a color ink, for example, a cyan, magenta, or yellow ink containing a color coloring agent other than the black coloring agent. The ink set may further comprise third and fourth coloring agents having colors different from those of the first and second coloring agents respectively. It is necessary that the water-soluble organic solvents contained in the first ink and the second ink of the ink set of the present invention have their solubility parameters &dgr;1, &dgr;2 which satisfy the relationship of 4≦|&dgr;1−&dgr;2|. The water-soluble organic solvent in each of the inks may be based on a single species or a mixed system containing a plurality of species. However, even when a plurality of water-soluble organic solvents are contained in the first ink, it is necessary that any one of the water-soluble organic solvents contained in the first ink satisfies the relationship of 4≦|&dgr;1−&dgr;2 |for the solubility parameters &dgr;1, &dgr;2 with respect to the water-soluble organic solvent contained in the second ink. When a plurality of water-soluble organic solvents are contained in each of the first ink and the second ink, it is necessary that any one of the water-soluble organic solvents contained in the first ink satisfies the relationship of 4≦|&dgr;1−&dgr;2|for the solubility parameters &dgr;1, &dgr;2 with respect to any one of the water-soluble organic solvents contained in the second ink.
According to a second aspect of the present invention, there is provided an ink cartridge to be used for an ink-jet or ink-jetting type recording apparatus, comprising:
a first compartment which accommodates a first ink containing water, a first coloring agent, and a water-soluble organic solvent; and
a second compartment which accommodates a second ink containing water, a second coloring agent different from the first coloring agent, and a water-soluble organic solvent, wherein:
a solubility parameter &dgr;1 of the water-soluble organic solvent contained in the first ink satisfies a relationship of 4≦|&dgr;1−&dgr;2|with respect to a solubility parameter &dgr;2 of the water-soluble organic solvent contained in the second ink.
The water to be used in the present invention is not specifically limited. However, it is preferable to use water having high purity such as ion exchange water and distilled water excluding, for example, tap water. The content of the water may be determined depending on the type and the composition of the coloring agent and the water-soluble organic solvent or the characteristics of the desired ink. However, in general, it is preferable that the content is 10 to 97% by weight with respect to the total weight of the ink. If the content is less than 10% by weight, then the viscosity of the ink is too high, and it is difficult to discharge the ink from the head. If the content exceeds 97% by weight, the ink is apt to be dried. The content is more preferably 30 to 95% by weight, and much more preferably 40 to 90% by weight.
Those usable as the coloring agent to be used in the present invention include, for example, dyes and pigments. Those usable as the dye include, for example, water-soluble dyes represented by direct dye, acidic dye, basic dye, and reactive dye. The water-soluble dye is not specifically limited. However, it is preferable to use those which are adequate for the ink to be used for the ink-jet recording system and which satisfy required performance such as vividness, water solubility, stability, light resistance, and other required performance, including, for example, C. I. Direct Black 17, 19, 32, 51, 71, 108, 146, 154, 168; C. I. Direct Blue 6, 22, 25, 71, 86, 90, 106, 199; C. I. Direct Red 1, 4, 17, 28, 83, 227; C. I. Direct Yellow 12, 24, 26, 86, 98, 132, 142; C. I. Direct Orange 34, 39, 44, 46, 60; C. I. Direct Violet 47, 48; C. I. Direct Brown 109; C. I. Direct Green 59; C. I. Acid Black 2, 7, 24, 26, 31, 52, 63, 112, 118; C. I. Acid Blue 9, 22, 40, 59, 93, 102, 104, 113, 117, 120, 167, 229, 234; C. I. Acid Red 1, 6, 32, 37, 51, 52, 80, 85, 87, 92, 94, 115, 181, 256, 289, 315, 317; C. I. Acid Yellow 11, 17, 23, 25, 29, 42, 61, 71; C. I. Acid Orange 7, 19; C. I. Acid Violet 49; C. I. Basic Black 2; C. I. Basic Blue 1, 3, 5, 7, 9, 24, 25, 26, 28, 29; C. I. Basic Red 1, 2, 9, 12, 13, 14, 37; C. I. Basic Violet 7, 14, 27; and C. I. Food Black 1, 2.
The pigmen
Aoyama Michiko
Fujioka Masaya
Goto Kazuma
Higashiyama Shunichi
Kobayashi Naomichi
Barlow John
Brooke Michael S
Brother Kogyo Kabushiki Kaisha
Oliff & Berridg,e PLC
LandOfFree
Ink set for ink-jet recording 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 set for ink-jet recording, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ink set for ink-jet recording will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3166271