Incremental printing of symbolic information – Ink jet – Fluid or fluid source handling means
Reexamination Certificate
2001-03-05
2004-03-02
Meier, Stephen D. (Department: 2853)
Incremental printing of symbolic information
Ink jet
Fluid or fluid source handling means
C347S095000, C106S031130
Reexamination Certificate
active
06698875
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to an ink set, an ink cartridge, and a recording method using same, and a recording material and recording apparatus therefor. More particularly, the present invention relates to an ink set and ink cartridge which allow color printing of an image having an excellent color reproduction with a plurality inks using an ink jet recording apparatus and provide a good discoloration resistance and color developability, a recording method using the ink set and ink cartridge, a recorded material thus obtained, and a recording apparatus therefor.
BACKGROUND OF THE INVENTION
As well known, an ink jet recording method is a printing method which comprises allowing ink droplets to fly so that they are attached to a recording medium such as paper to effect printing. This printing method allows fast and easy printing of a high resolution and quality image using an inexpensive apparatus. In particular, in the art of color printing with a plurality of inks (magenta, cyan, yellow inks), this printing method has been recently under technical development to provide an image forming method substitute for photography.
An ink normally comprises water as a main component having a colorant component, a wetting agent for preventing clogging such as glycerin, a penetrating agent, etc. incorporated therein. As the plurality of color inks to be used in the ink jet recording method there are used a dye ink (ink comprising a “dye” incorporated therein as a colorant) and a pigment ink (ink comprising a “pigment” incorporated therein as a colorant).
(Problem 1 of the Background Art)
As the colorant to be incorporated in the dye ink there is used particularly a “water-soluble dye” from the standpoint of advantages of high image quality such as high color saturation and color reproducibility, abundance in colorants which can be used, solubility in water, reliability in resistance to clogging, and ability to represent a color having a good transparency on a recording medium.
However, the dye ink is disadvantageous in that it is inferior to the pigment ink in respect to properties such as light fastness and water fastness. This difficulty becomes remarkable particularly in a low image density range (so-called highlight range).
On the other hand, the pigment ink is advantageous in that it allows printing of characters and images with little bleeding as compared with the dye ink. Further, a pigment ink is excellent in light fastness and water fastness as compared with a dye. In recent years, the use of a pigment as a colorant for ink jet recording ink has been studied for the purpose of improving light fastness and water fastness.
However, the pigment ink is disadvantageous in that it is inferior to the dye ink in respect to color developability. Further, since a pigment is normally insoluble in water, in order to incorporate a pigment in an aqueous ink, the pigment has to be uniformly dispersed in water in the form of mixture with a resin called dispersant to provide the resulting ink with a prolonged reliability. However, when all colors are provided by pigments, it is disadvantageous in that a desired dispersion stability can hardly be secured.
Further, unlike one obtained with an aqueous ink comprising a dye incorporated therein, a printed matter obtained with an aqueous ink comprising a pigment incorporated therein has some pigment left on the surface thereof and thus can hardly resist scratching. Moreover, when all colors are provided by pigments, the resulting inks exhibit a poor transparency (color developability) and hue and hence a low color reproducibility.
In an attempt to eliminate these difficulties and disadvantages, the combination of a dye ink and a pigment ink has heretofore been proposed. For example, JP-A-5-148441 (The term “JP-A” as used herein means an “unexamined published Japanese patent application”) discloses a “recording liquid suitable for ink jet printer, and ink jet recording method using same” involving the use of specific “dye and pigment” as colorant for magenta ink. Further, JP-A-5-155004 discloses a “color image forming method by ink jet recording method” involving the use of a specific dye as colorant for yellow ink and a specific pigment as colorant for magenta ink and cyan ink. Moreover, JP-A-5-155005 discloses a “color image forming method by ink jet recording method” involving the use of a specific dye as colorant for yellow ink and cyan ink and a specific pigment as colorant for magenta ink.
However, none of the approaches disclosed in the above cited patents can eliminate the foregoing difficulties and disadvantages. In particular, the problem that a dye ink is remarkably disadvantageous in properties such as light fastness and water fastness in a low image density range (highlight range) cannot be solved.
(Problem 2 of the Background Art)
Among the color dye inks (yellow, magenta, cyan), the magenta ink is particularly disadvantageous in that it exhibits a deteriorated light fastness. Thus, when irradiated with light, the resulting image exhibits an ill-balanced hue and thus shows a remarkably deteriorated quality. Further, discoloration is accelerated not only in single magenta color but also in blue color represented by magenta and cyan in combination to cause drastic deterioration of image quality.
Further, when inks having the same hue but different densities (dark-colored and light-colored inks) are used to reduce the graininess on a range from a low image density range (highlight range) to middle tone range, a photograph-like image can be obtained. However, the light-colored ink exhibits a far low light fastness than the dark-colored ink). The light-colored magenta ink is remarkable in this tendency. Further, the area having magenta and cyan in mixture can undergo rapid discoloration due to deterioration by light. This in presumably attributed to harmful radicals or active oxygen (singlet oxygen), etc. produced by light.
(Problem 3 of the Background Art)
As the foregoing “ink jet recording medium” on which image recording is effected with a water-soluble dye there is known an “ink jet recording medium having a porous ink-receiving layer provided on a substrate” which allows printing of an image having an excellent water fastness and a high quality that can dry quickly.
However, a recorded material obtained by ejecting the foregoing water-soluble dye onto an ink jet recording medium having a porous ink-receiving layer provided an a substrate is subject to discoloration due to gases such as ozone (O
3
), nitrogen oxide (NO
x
) and sulfur oxide (SO
x
) contained in the air when the dye contained in the ink as a colorant is brought into contact with the atmosphere because the ink-receiving layer is porous. In particular, among the color dye inks (yellow, magenta, cyan), some cyan dyes, though having a high water fastness and light fastness, exhibit a low gas resistance (C.I. direct blue 86, 199, etc.). Thus, there arises a problem that an image obtained with such a cyan dye having a copper phthalocyanine skeleton undergoes deterioration due to oxidation and reduction by gases and hence an ill-balanced hue that causes the image to show a remarkable deterioration. This problem becomes remarkable particularly in a low image density range (highlight range).
SUMMARY OF THE INVENTION
The inventors made extensive studies of an ink jet recording method using color inks, particularly a plurality of inks having different densities but the same hue (dark-colored ink and light-colored ink). As a result, it was found that the combination of specific pigment ink (at least one of light-colored inks is an ink containing a pigment as a colorant) and dye inks makes it possible to provide a high image quality, a high rub fastness and a high light fastness at the same time (A high quality image and a high rub fastness can be realized and discoloration can be effectively inhibited.). The present invention has thus been completed.
In other words, the present invention has been firstly worked out in the light of the foregoing “problems 1 to 3
Onishi Hiroyuki
Yamamoto Yuko
Ladas & Parry
Meier Stephen D.
Seiko Epson Corporation
Shah Manish
LandOfFree
Ink set and ink cartridge and recording method, 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 and ink cartridge and recording method, recording..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ink set and ink cartridge and recording method, recording... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3207062