Stock material or miscellaneous articles – Ink jet stock for printing – Modified polyvinyl alcohol ink receptive layer
Reexamination Certificate
2001-12-03
2004-03-02
Kelly, Cynthia H. (Department: 1774)
Stock material or miscellaneous articles
Ink jet stock for printing
Modified polyvinyl alcohol ink receptive layer
C428S032290, C428S032340
Reexamination Certificate
active
06699536
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to an ink jet recording sheet, and particularly to an ink jet recording sheet which exhibits excellent ink absorbability, minimizes bleeding, and results in high color density.
BACKGROUND OF THE INVENTION
In recent years, ink jet recording has increasingly resulted in enhancement of image quality which is approaching that of conventional photography. In order to achieve such conventional photographic quality, improvement has been made in the area of recording sheets. A void type recording sheet, which comprises a highly smoothened support having thereon a minute-void layer comprised of fine particles and hydrophilic polymers, exhibits high gloss, results in bright color formation, and exhibits excellent ink absorbability as well as ink drying properties. Accordingly, said recording sheet has been regarded as one of those which are most similar to conventional photographic quality. Specifically, when a non-water absorptive support is employed, it is possible to prepare high quality prints because cockling (wrinkling), which is noticed in a water absorptive support, is not present, and it is possible to maintain the highly smoothened surface.
Ink jet recording is mainly divided into two types; one in which ink, comprised of water-soluble dyes, is employed and the other in which ink, comprised of pigments, is employed. The ink comprised of pigments results in highly durable images but gloss tends to vary imagewise. As a result, it is difficult to prepare prints which exhibit conventional photographic quality. On the other hand, when an ink, comprised of water-soluble dyes, is employed, it is possible to obtain very bright and clear images of uniform gloss. Accordingly, it is possible to prepare color prints approaching conventional photographic quality.
However, ink, comprised of water-soluble dyes, results in disadvantages such as bleeding and poor water resistance due to the high hydrophilicity of said water-soluble dyes. Namely, when after printing, prints are stored at high humidity for a long period of time, or water droplets are allowed to adhere onto the print surface, said dyes tends to result in bleeding.
In order to overcome such drawbacks, it is a general practice to incorporate dye fixing materials such as cationic materials into a porous layer.
A method preferably employed is one in which, for example, an anionic dye is allowed to bond to a cationic polymer so as to be immobilized. Cited as such cationic polymers are polymers of quaternary ammonium salts, which are, for example, described in the conventional art of “Ink Jet Printer Gijutsu to Zairyo (Technology and Materials of Ink Jet Printers)”, (published by CMC Co., Ltd., July 1998) and Japanese Patent Publication Open to Public Inspection No. 9-193532.
Further, a method has been proposed in which water-soluble polyvalent metal ions are previously incorporated into an ink jet recording sheet so that during ink jet recording, dyes are immobilized while being coagulated and fixed.
However, when such cationic polymers and water-soluble polyvalent ions are incorporated to minimize bleeding as well as to enhance water resistance, said dyes tend to coagulate on the surface. As a result, the image surface tends to result in a bronzing phenomena, in which the image surface exhibits a metallic gloss. Said bronzing tends to generally occur when prints are stored in a highly humid environment.
The inventors of the present invention conducted investigations of said drawbacks and discovered that when specific cationic polymers and specific compounds having a zirconium or aluminum atom were incorporated, it was possible to minimize bleeding, as well as to enhance water resistance without bronzing.
It has been known that compounds containing a zirconium atom and an aluminum atom are employed in ink jet recording sheets.
Japanese Patent Publication Open to Public Inspection Nos. 55-53591, 55-150396, 56-867789, 58-89391, and 58-94491 describe ink jet recording sheets comprised of water-soluble polyvalent metal salts which bond to water-soluble dyes to form minimally water-soluble salts.
Further, Japanese Patent Publication Open to Public Inspection Nos. 60-67190, 61-10484, and 61-57379 describe ink jet recording sheets comprised of cationic polymers as well as water-soluble polyvalent metal salts.
Japanese Patent Publication Open to Public Inspection No. 60-257286 describes an ink jet recording sheet comprised of basic polyhydroxyl aluminum compounds.
Further, Japanese Patent Publication Open to Public Inspection No. 10-258567 discloses a method employing a hydrophilic polymer and a water-soluble compound comprising a 4A group element, in combination, while Japanese Patent Publication Open to Public Inspection No. 10-309862 discloses a method employing a hydrophilic polymer together with a polyhydric carboxylic acid, and a zirconyl compound, also in combination.
Further, regarding compounds comprising said zirconium element, Japanese Patent Publication Open to Public Inspection No. 4-7189 discloses a method employing a porous pigment and an acid zirconium chloride compound. Said patent specification describes that by adding said acid zirconium chloride salt, desired adhesion strength is obtained employing a relatively small amount of binder, and it is possible to achieve improvement of image quality.
Japanese Patent Publication Open to Public Inspection No. 6-32046 discloses a method in which a zirconium compound is combined with silica and modified polyvinyl alcohol
Further, European Patent No. 754,560 discloses that a water-soluble binder, a pigment, a zirconium compound, and a cationic polymer are employed in combination.
However, the prior art, as above, does not describe effects to minimize bronzing of prints. It was verified that in some cases, more bronzing resulted.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an ink jet recording sheet in which, after printing, the water-soluble dye results in minimized bleeding during storage and improvement in water resistance.
Another object of the present invention is to provide an ink jet recording sheet in which the ink absorption rate is improved without enhancing bleeding.
Said objects as above were achieved employing the constitution described below.
1. An ink jet recording sheet comprising a support having thereon a porous ink absorptive layer comprising inorganic particles, polyvinyl alcohol, at least two cationic polymers having a quaternary ammonium salt group in the molecule, and a compound containing a zirconium atom or an aluminum atom other than zirconium oxide and aluminum oxide.
2. The ink jet recording sheet of item 1, wherein said cationic polymers are represented by Formula (1) or by Formula (2),
wherein R represents a hydrogen atom or an alkyl group; R
1
, R
2
, and R
3
each represent an alkyl group or a benzyl group; J represents a bond or a divalent organic group; X
−
represents an anion group; A represents a repeating unit having no quaternary ammonium salt group; l represents an integer of 1 to 6; x represents 5 to 100 mol %; and y represents 0 to 95 mol %,
wherein Q represents a repeating unit represented by Formula (2A), (2B), or (2C); A represents a repeating unit having no quaternary ammonium salt group, x′ represents 5 to 100 mol % and y′ represents 0 to 95 mol %,
wherein R, R
1
, R
2
, and R
3
, and X
−
are the same as defined for R, R
1
, R
2
, and R
3
, and X
−
of Formula (1); J
1
represents a bond or a divalent organic group; B represents —O— or —N(R
5
)—, wherein R
5
represents a hydrogen atom, an alkyl group, an allyl group, or a benzyl group; and m represents an integer of 1 to 6,
wherein R and X
−
are the same as defined for R and X
−
of Formula (1); J
1
is the same as defined above for J
1
of Formula (2A); and R
4
represents an alkyl group,
wherein R and X
−
are the same as defined for R and X
−
of Formula (1), and R
4
is the same as defined for R
4
of Formula (2B).
3. An ink jet recording she
Katoh Eisaku
Tsubaki Yoshinori
Kelly Cynthia H.
Konica Corporation
Muserlian Lucas and Mercanti
Shewareged B.
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