Incremental printing of symbolic information – Ink jet – Medium and processing means
Reexamination Certificate
2001-12-21
2003-08-19
Hallacher, Craig (Department: 2853)
Incremental printing of symbolic information
Ink jet
Medium and processing means
C428S195100
Reexamination Certificate
active
06607269
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an ink-jet recording material, particularly to an ink-jet recording material that has photo-like high glossiness, is excellent in ink-absorption property, and is improved in preservability after printing, and an ink-jet recording method.
2. Prior Art
As a recording material to be used for an ink-jet recording method, it has been known a recording material which comprises an ink-receptive layer made of a hydrophilic polymer or a porous ink-receptive layer containing a pigment such as amorphous silica, etc. and a hydrophilic polymer, being provided on a support such as a usual paper or the so-called ink-jet recording sheet.
There have been proposed recording materials obtained by coating a silicon-containing pigment such as silica, etc., with an aqueous binder onto a paper support as disclosed in, for example, Japanese Provisional Patent Publications No. 51583/1980, No. 157/1981, No. 107879/1982, No. 107880/1982, No. 230787/1984, No. 160277/1987, No. 184879/1987, No. 183382/1987, No. 11877/1989, No. 21508/1991, No. 67986/1992 and the like.
Also, in Japanese Patent Publication No. 56552/1991, Japanese Provisional Patent Publications No. 188287/1990, No. 132728/1996, No. 81064/1998, No. 119423/1998, No. 175365/1998, No. 193776/1998, No. 203006/1998, No. 217601/1998, No. 20300/1999, No. 20306/1999 and No. 34481/1999, and the like, there have been disclosed ink-jet recording materials using synthetic silica fine particles prepared by a gas phase process (hereinafter referred to as “fumed silica”). Ultrafine particles having an average particle size of the primary particle of 30 nm or less, particularly fumed silica have characteristics that they give a recording material having good ink absorption property and high glossiness. In recent years, a recording sheet having characteristics like photography has earnestly been desired. Recording materials in which an ink-receptive layer mainly comprising fumed silica had been coated on a water-resistant support such as a polyolefin resin-coated paper (a polyolef in resin such as polyethylene, etc., is laminated on the both surfaces of paper) and a polyester film have been proposed.
A paper support which has conventionally been used in general has itself a role of an ink-receptive layer. However, different from a paper support, the water-resistant support such as a polyolefin resin-coated paper, etc. cannot absorb ink so that it is important that an ink-receptive layer provided on the support has a high ink absorption property whereby it is necessary to heighten voids of the ink-receptive layer. Accordingly, to prepare a recording sheet using a water-resistant support, it is necessary to increase an amount of the fumed silica to be coated, and further to reduce a ratio of a binder to the fumed silica.
However, in ink-jet recording materials having high voids using ultrafine particle fumed silica, whereas its ink-absorption property is extremely excellent, there are problems that its light resistance is poor or a printed image likely discolors during preservation after printing. That is, in a recording medium having a void layer of fumed silica, a problem of poor light resistance, particularly a problem of likely causing discoloration due to a minute amount of a gas in air is not yet sufficiently resolved.
Compounds which have been known as an agent for preventing discoloration due to a minute amount of a gas or a light resistance-improving agent cannot improve both of gas resistance (an effect of preventing discoloration due to a minute amount of a gas) and light resistance simultaneously when they are added to a porous ink-receptive layer comprising ultrafine silica particles since there is an effect of preventing discoloration due to a minute amount of a gas but light resistance becomes poor, or else gas resistance becomes poor while light resistance is improved. Thus, it is the present status that there is little compound which improves both of gas resistance and light resistance simultaneously.
In Japanese Provisional Patent Publication No. 25796/1996, there is disclosed that gas resistance can be improved by adding a compound such as a thiourea derivative, etc., to a porous ink-receptive layer comprising pseudo-boehmite. Gas resistance is certainly improved with a great extent when thiourea is added to the porous ink-receptive layer comprising ultrafine silica particles, and light resistance is also improved with a certain extent. However, the thiourea derivatives are supposed to have bad effects on human body so that its use is limited.
In Japanese Provisional Patent Publication No. 314882/1995, there is disclosed that gas resistance can be improved by adding a compound such as a dithiocarbamate, etc., to a porous ink-receptive layer comprising pseudo-boehmite. However, even when dithiocarbamic acid is added to the porous ink-receptive layer comprising ultrafine silica particles, gas resistance is not improved and light resistance becomes worse.
In Japanese Provisional Patent Publication No. 314881/1995, there is disclosed that yellow discoloration at the time of contacting with a polyvinyl chloride film can be prevented by adding a urea derivative, a semicarbazide derivative, a carbohydrazide derivative or a hydrazine derivative to a porous ink-receptive layer comprising pseudo-boehmite. However, even when urea is added to the porous ink-receptive layer comprising ultrafine silica particles, both of gas resistance and light resistance can be hardly improved.
Also, in Japanese Provisional Patent Publication No. 154989/1986, there is disclosed that light resistance can be improved by adding a hydrazide series compound to an ink-receptive layer comprising synthetic silica, but there is no description to improve gas resistance.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide a material for an ink-jet recording that has photo-like high glossiness, high ink-absorption capacity and high water resistance, and is improved in preservability.
The above objects of the present invention can be accomplished by an ink-jet recording material which comprises a water resistant support, and a porous ink-receptive layer containing inorganic fine particles having an average particle size of a primary particle of 30 nm or less provided on the support, wherein said ink-jet recording material contains at least one hydrazine compound.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred ink-jet recording material of the present invention is characterized in that it can absorb ink in voids in the film formed by fumed silica, and in order to realize high ink-absorption capacity, it is necessary to increase a void volume. Therefore, it is necessary to coat a relatively large amount of the fumed silica on the support, and when a hydrophilic binder is used, its amount is preferably reduced to increase the voids (or a void ratio).
The fumed silica with ultrafine particles to be preferably used in the present invention is preferably added to an ink-receptive layer in an amount of 8 g/m
2
or more, more preferably in the range of about 10 to 30 g/m
2
. If the amount is less than the above range, ink-absorption capacity is deteriorated. An amount of the hydrophilic binder is preferably in the range of 10 to 40% by weight based on the amount of the fumed silica fine particles. By decreasing the ratio of the hydrophilic binder as mentioned above, ink-absorption capacity is improved but water resistance, and light resistance and gas resistance after printing are likely deteriorated. The present invention satisfies these properties simultaneously.
In the present invention, the fumed silica fine particles are preferably contained in an ink-receptive layer as a main component. That is, an amount of the inorganic (or fumed silica) fine particles is preferably 50% by weight or more, more preferably about 60% by weight or more, further preferably about 65% by weight or more based on the total weight of the whole solid components in the ink-receptive
Haino Kozo
Hanmura Masahiro
Onishi Hiroyuki
Sakaguchi Hiroshi
Sumioka Ko-ichi
Hallacher Craig
Manelli Denison & Selter PLLC
Mitsubishi Paper Mills Limited
Shah Manish S.
White, Jr. Paul E.
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