Stock material or miscellaneous articles – Ink jet stock for printing – Plural ink receptive layers
Reexamination Certificate
2001-03-30
2003-11-25
Hess, Bruce H. (Department: 1774)
Stock material or miscellaneous articles
Ink jet stock for printing
Plural ink receptive layers
C428S032300, C428S032340, C428S032370
Reexamination Certificate
active
06652931
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a recording material for ink-jet recording. More specifically, the invention is concerned with a recording material which has good ink absorbency and excellent color reproducibility, can provide high-quality images of a photograph style, and can ensure excellent keeping properties, particularly light resistance, in the images printed thereon by an ink-jet printer.
BACKGROUND OF THE INVENTION
Ink-jet recording methods enable full-color printing to be easily achieved with a low noise level. In recent years, therefore, the utilization of ink-jet recording methods has been spreading at a rapid rate. According to such methods, fine drops of ink are jetted from nozzles at a high speed so as to direct toward a recording material. And a large quantity of solvent is contained in the ink used. As a result, recording materials for ink-jet recording are required to absorb ink promptly. The recent years have also seen rapid proliferation of personal computers and digital cameras. Under these circumstances, image qualities on a level similar to those attained by silver salt photography have come to be required for images printed from digital image information. In other words, it has become necessary for recording materials to ensure high-density colors, high resolution and excellent color reproduction in the images printed from digital information.
Moreover, latest improvements in quality of printed images have made the storage stability of recorded images more important. In the ink-jet recording systems employed at present, acid dyes or direct dyes are most commonly used as printing ink because they can avoid clogging a printing head with ink and ensure high saturation in the ink images recorded, but these dyes do not always have satisfactory resistance to water and light.
With the intention of imparting both water resistance and light resistance to printed images, it has been tried to use various compounds in recording layers. For instance, the use of particular cationic resins such as quaternary compounds of polyethyleneimine is disclosed in Japanese Tokkai Sho 59-198188 (the term “Tokkai” as used herein means an “unexamined published patent application”), the use of colloidal cationic silica in Japanese Tokkai Sho 60-260377, the use of hindered amine compounds in Japanese Tokkai Sho 61-146591, and the use of quaternary ammonium salts of polyoxyalkylenated amine monocarboxylic acid esters in Japanese Tokkai Sho 61-284478. However, those compounds have a measure of improving effect on water resistance of images, but their effects produced on improvements of light resistance are still insufficient. As matters now stand, therefore, no compounds capable of ensuring both water resistance and light resistance in printed images are found yet.
For the purpose of enhancing the light resistance in particular, the addition of ultraviolet absorbents and antioxidants to recording layers are disclosed in Japanese Tokkai Sho 57-87988 and Japanese Tokkai Sho 57-87989 respectively. Although it can be recognized that those methods have effects on improvement of light resistance, the improving effects thereof are insufficient for practical use. In addition, it is admitted that those methods cause troubles in printed image quality. More specifically, the former method of adding ultraviolet absorbents causes serious reduction in color reproduction, and fails to provide images of photographic style from the very beginning of printing; while the latter method of adding antioxidants has a defect that the antioxidants themselves turn brown with the lapse of time and thereby a storage stability problem is caused in white areas of the recording paper containing them.
With the current state of the art, therefore, it is unsuccessful to produce recording paper capable of providing images of photograph style, and at the same time, inhibiting the images from deteriorating under exposure to light, water and gases, and further having excellent keeping quality to avoid discoloring in the white area.
SUMMARY OF THE INVENTION
Therefore, an object of the invention is to provide a recording material which can produce images having high densities and excellent color reproduction, or images of the so-called photograph style, when the color printing with an ink-jet printer, particularly a high-resolution ink-jet printer, is done thereon, and ensure excellent keeping quality, especially high resistance to light, in the printed images.
In the cases where improvements in keeping quality of recorded images, inclusive of water resistance and light resistance, have been intended in the field of ink-jet recording as well as various other fields, it has so far been a common-sense way to add keeping quality-improving chemicals to recording layers or provide a protective layer containing such chemicals on the upper side of a recording layer. This is because light and water influence a printed image surface from the outside and cause deterioration of keeping quality in the printed images. However, since the ink-jet recording is a recording method of jetting ink directly to the surface of an ink-receptive layer and forming ink images thereon, it is ineffective to provide a protective layer on the outside of the ink-receiving layer. Further, the coloring materials used in ink are direct dyes or acid dyes. These dyes are superior in coloring properties, but they are subject to cleavage of double bonds in their structures by ultraviolet rays or oxidizing gases and thereby their oxidation is promoted to result in discoloration or fading. In addition, those dyes are liable to be affected by various chemicals. Therefore, the addition of other chemicals to an image-forming layer carries the risk of directly producing adverse effects on coloring properties.
As a result of our intensive studies to resolve the foregoing antinomic problem, to our surprise, it has been found that as far as light resistance-imparting chemicals are added to a layer provided beneath an image-forming layer, but not to the image-forming layer by which ink is directly accepted, they enables significant improvement in light resistance and, at the same time, complete avoidance of their adverse effects on coloring properties of dyes which has so far been a problem to be addressed.
More specifically, the aforementioned problem is resolved by structuring a recording material for ink-jet recording so as to comprise a support coated with a light resistance-imparting layer containing a light resistance-imparting chemical and an image-forming layer free of a light resistance-imparting chemical in the order described.
Further, the foregoing recording material for ink-jet recording can acquire a more suitable balance between ink absorbency and color reproduction of images when the light resistance-imparting layer has a coverage of 5 to 20 g/m
2
(on a dry basis) and the image-forming layer has a coverage of 4 to 20 g/m
2
(on a dry basis).
Furthermore, the light resistance of the recording material as mentioned above can be greatly increased when the light resistance-imparting chemical contained in the light resistance-imparting layer is at least one chemical selected from inorganic ultraviolet absorbents, organic ultraviolet absorbents, or divalent or higher metal salts, and the content thereof is from 0.5 to 20 parts by weight when it is an inorganic ultraviolet absorbent, from 0.5 to 15 parts when it is an organic ultraviolet absorbent, or from 0.5 to 10 parts by weight when it is a divalent or higher metal salt, per 100 parts by weight of pigments contained in the light resistance-imparting layer.
In addition, the light resistance of the recording material as mentioned above can be further increased when the light resistance-imparting chemical contained in the light resistance-imparting layer is at least one organic ultraviolet absorbent selected from the group consisting of hindered amines, benzotriazoles and benzophenones, or at least one inorganic ultraviolet absorbent selected from the group consisting of zinc oxide, tita
Kondo Noboru
Ono Atsushi
Otani Teiichi
Hess Bruce H.
Millen White Zelano & Branigan P.C.
Nippon Paper Industries Co. Ltd.
Shewareged B.
LandOfFree
Recording material 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 Recording material for ink-jet recording, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Recording material for ink-jet recording will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3149574