Stock material or miscellaneous articles – Ink jet stock for printing – Dye-fixing agent in ink receptive layer
Reexamination Certificate
2000-03-30
2004-11-09
Shewareged, B. (Department: 1774)
Stock material or miscellaneous articles
Ink jet stock for printing
Dye-fixing agent in ink receptive layer
C428S032340, C428S032380
Reexamination Certificate
active
06815021
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a recording medium, and in particular, relates to a technique for improving color stability and image recording quality such as printing density, ink absorptivity, and image shelf-life.
An ink jet recording technique in which a water-soluble ink is output and printed on a medium for recording has characteristics such as vividness of recorded images, as well as high speed, low noise, ease of coloring, etc., whereby, the popularization thereof has increased in recent years. As a recording medium which effectively reflects the characteristics of the ink jet recording technique, the following recording medium has been provided. The recording medium is one in which an ink receiving layer having characteristics, in which water-soluble ink is sufficiently absorbed, thereby yielding in vivid images, is laminated on the surface of a supporting material such as paper primarily made from pulp. A coating solution is prepared by dispersing pigment in an ink receiving agent such as silica and binder resin such as carboxyl modified polyvinyl alcohol. An ink receiving layer is laminated thereon by coating the coating solution on the surface of a supporting material.
However, in recent years, typical ink jet printers using ink jet recording techniques are becoming cheaper, and vivid coloration of printed images is anticipated. As a result, such printers are often used professionally, such as in color proofreading (for example, test printing in plate-making step), etc. In this case, the required level of color stability is increased, as is the image recording quality such as printing density, ink absorbability (high-speed printing property), image shelf-life (light resistance, water resistance, moisture resistance, etc.). Therefore, in order to expand applications of a recording medium for ink jet printers, it is necessary that requirements for these properties be sufficiently satisfied in the present situation.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a recording medium for ink jet printers in which all properties such as color stability and image recording quality, e.g., printing density, ink absorptivity, and image shelf-life can be exhibited at high levels.
According to the results that the inventors have obtained from various research with regard to a recording medium for ink jet printers, in which an ink receiving layer containing at least pigment and binder resin is coated on a supporting material, a recording medium for ink jet printers in which the image recording quality such as printing density, ink absorptivity, image shelf-life (light resistance, water resistance, moisture resistance, etc.), and the like are superior and in which color stability is preferable, can be obtained by containing a specific water-soluble material as a color stability improving component in an ink receiving layer, and have thereby attained the present invention. The color stability in the present invention is defined as a property in which the values of CIE L*, a*, and b* of color directly after recording do not change as time elapses, that is to say, a property in which the values of CIE L*, a*, and b* of the ultimate target color are achieved in the shortest time. In other words, it is defined as a property in which the color difference &Dgr;E between the color immediately after recording and that after time has elapsed does not increase as time elapses. As a color stability improving component to be contained therein, partially saponified polyvinyl alcohol, acetoacetyl modified polyvinyl alcohol, carboxylic acid modified polyvinylacetal, polyethylene glycol derivatives, and secondary alcohol ethoxylate type surfactants, can be employed alone or in combination. The present invention further specifies these components. In the following, materials composing the recording medium for ink jet printers according to the present invention will be explained.
(1) Supporting Material
As a supporting material provided for an ink receiving layer, a base paper which is mixed wood pulp, such as a chemical pulp such as LBKP, NBKP, or the like; mechanical pulp such as GP, PGW, RMP, TMP, CTMP, CMP, CGP, or the like; recycled pulp such as DIP, or the like; etc.; or synthetic fiber pulp such as polyethylene fiber, or the like, as a primary component, with pigment and any type of additive which is typically employed in paper, such as sizing agents, yield improving agents, strengthening agents, or the like, alone or in combination, as necessary, and produced by using any type of paper-making apparatus such as a fourdrinier paper machine, cylinder paper machine, twin wire paper machine, or the like; can be preferably employed. In addition, a base paper provided with starch, polyvinyl alcohol, casein, gelatin, or the like using a size press; a base paper provided with an anchor coat layer; an art paper, a coated paper, a cast coat paper, or the like, in which baryta paper treatment is carried out so as to be usable for photographic printing papers, can be preferably employed. These supporting materials are provided with an ink receiving layer thereon; however, in order to improve smoothness or coating property of the ink receiving layer, or to produce a finish like that of photographic print paper, these supporting materials may be further calendered before coating the ink receiving layer thereon, using a calender apparatus such as a machine calender, TG calender, soft calender, or the like.
In the case in which a laminate material is employed on the supporting material, synthetic resin such as polyolefin, polyethylene, polypropylene, polyester, nylon, rayon, polyurethane, etc., and film material comprised of these synthetic resins, which is porous from the beginning in order to prevent air resistance from being too high, or which is a very thin film so as to become porous by heating, etc., may be employed.
In order to optimally design the recording medium for ink jet printers, it is preferable that the smoothness of the coating surface on the supporting material be increased to be as high as possible by a method in which the rigidity thereof is not deteriorated. As a value for the smoothness, the smoothness measured by the Ohken method smoothness test according to “J. TAPPI paper and pulp test method No. 5” is preferably 100 seconds or more, is more preferably 500 seconds or more, and is most preferably 1500 seconds or more. In the case in which the rigidity of the supporting material is too low or is too high, problems are likely to occur in paper feed processes through printers. Therefore, a rigidity measured at 20° C. and 65% RH by the Gurley method rigidity test according to “J. TAPPI paper and pulp test method No. 40” is preferably 400 to 3600 mN in the machining direction and 200 to 1800 mN in the cross direction, and is more preferably 800 to 2500 mN in the machining direction and 400 to 1000 mN in the cross direction.
(2) Ink Receiving Layer
A. Pigment
In an ink receiving layer according to the present invention, generally, well-known pigments which are insoluble or slightly soluble in water can be employed alone or in combination. For example, a white inorganic pigment such as precipitated calcium carbonate, heavy calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, aluminum silicate, diatomite, calcium silicate, magnesium silicate, synthetic amorphous silica, colloidal silica, colloidal alumina, pseudo-boehmite, aluminum hydroxide, alumina, lithopone, zeolite, hydrolytic halloysite, magnesium carbonate, magnesium hydroxide, etc.; an organic pigment such as styrene-type plastic pigment, acrylic-type plastic pigment, polyethylene, microcapsules, urea resin, melamine resin, etc., or the like, can be employed.
A primary component in the ink receiving layer is generally composed of a white pigment. As such a white pigment, a porous inorganic pigment is preferable since drying properties and absorptivity of inks for ink jet printers is superi
Asai Shigeki
Ishikawa Takayuki
Ishikawa Yukari
Iwamoto Kiyoshi
Kubota Nobuhiro
Scully Scott Murphy & Presser
Shewareged B.
LandOfFree
Recording medium for ink jet printers 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 medium for ink jet printers, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Recording medium for ink jet printers will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3361398