JP2002086902A - Ink-jet recording medium and its production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ink-jet recording medium with the discoloration of a print by light, etc., reduced. SOLUTION: In the ink-jet recording medium in which an ink receiving layer is formed at least on one side of a base material, fine calcium carbonate particles coated with aluminum or silicon oxide are used as a main component in at least one layer of the ink receiving layer, and a cationic component is used as another component. The recording medium can be produced by coating at least one surface of the base material or a base material having an under layer with a coating containing at least fine calcium carbonate particles coated with aluminum or silicon oxide and a binder which is cationic or contains another cationic component and drying the coating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording material which is less likely to be discolored or printed by light or the like, and to a method for producing the same.

[0002]

2. Description of the Related Art Ink jet printers for jetting liquid ink from a nozzle having a special structure in a jet form, controlling the trajectory thereof and attaching the ink to a sheet of paper, and widely printing are used for printers such as facsimile machines, word processors, and personal computers. Have been. The paper used for this purpose includes the fixing properties and absorbency of inkjet ink, print density, roundness of dot shape, sharpness around dots, whiteness, water resistance and dimensional stability due to moisture absorption and desorption. An ink jet recording material having the above characteristics is used.

In order to obtain printing quality characteristics among these characteristics, it is generally effective to provide a coating layer containing silica as a main component, and many papers currently on the market are provided with the coating layer. ing. In order to increase whiteness, whitening agents such as fluorescent dyes, color dyes and pigments
A color adjusting agent or the like is used.

[0004] However, among the above-mentioned ink jet recording materials, particularly, recording materials on which photographs or graphic data are printed are used for applications such as decorating a wall or the like, or being used as a display, or exposed to light, or as an album or a collection of works. It is often used for long-term storage, and there is an increasing demand for an ink jet recording material having not only high print quality but also little discoloration.

[0005]

However, the silica used in the surface coating has a very high surface activity and is effective in improving the printing quality, but on the other hand, the dye of the ink jet ink and the fluorescent dye, the color dye and the pigment in the paper are used. And has the effect of accelerating the discoloration of the whitening agent / color matching agent.

An object of the present invention is to eliminate the disadvantages of the conventional examples and to provide an ink jet recording material having not only high whiteness and high printability but also little discoloration.

[0007]

Means for Solving the Problems The inventors of the present invention have made intensive studies to achieve the above object, and as a result, in an ink jet recording material having an ink receiving layer formed on at least one surface of a substrate, By using calcium carbonate fine powder coated with aluminum or silicon oxide as a main component of at least one layer of the ink receiving layer, and using a cationic component in combination with other components, high whiteness and high printing It has been found that not only characteristics but also an ink jet recording material with less discoloration due to light or the like can be obtained.

In general, the coating liquid for the ink-jet receiving layer is often composed of a cationic (acidic) component to supplement the dye particles of the ink, but calcium carbonate decomposes when it comes in contact with the acidic component. In order to prevent this, in the present invention, the surface of calcium carbonate is coated with aluminum or silicon oxide. This makes it possible to suppress decomposition in an acidic solution.

Regarding the printing characteristics, since calcium carbonate itself is porous, excellent printing characteristics are obtained even when calcium carbonate coated with aluminum or silicon oxide is used as a pigment for an ink jet receiving layer.

Further, since calcium carbonate itself has a high whiteness, a high whiteness can be ensured even when calcium carbonate coated with aluminum or silicon oxide is used as a pigment of the ink jet receiving layer, and the whiteness of the ink jet receiving layer can be ensured. It is considered that the amount of the fluorescent dye used to improve the image quality can be reduced, and the discoloration and discoloration of the print can be significantly suppressed.

The calcium carbonate may be coated with aluminum or silicon oxide by any method as long as it coats the inorganic oxide on the powder. The amount which can cover the monomolecular layer with calcium carbonate is preferable. The particle size of calcium carbonate coated with aluminum or silicon oxide is preferably 1 to 20 μm. If the particle diameter is 1 μm or less, it is not possible to secure a sufficient space for absorbing the ink. If the particle diameter is 20 μm or more, feathering after printing becomes conspicuous, and the printing quality deteriorates. Further, the oil absorption amount according to the JIS K-5421 method is 200 to 10
By using calcium carbonate coated with 00 ml / 100 g of aluminum or silicon oxide, a recording material having high ink absorbency can be obtained.

On the other hand, calcium carbonate fine powder to be a base is roughly classified into light calcium carbonate and heavy calcium carbonate, and either one may be used as a base. The former may be used when the texture is used as glossy, and the latter may be used when used as matte.

The pigment component used in at least the outermost layer of the ink receiving layer may be a single calcium carbonate fine powder coated with aluminum or silicon oxide.
Other pigments, for example, silica, alumina, resin particles, various coloring pigments and the like may be used in combination. However, the calcium carbonate fine powder coated with aluminum or silicon oxide is preferably at least 20%, more preferably at least 50% of the total pigment.

To fix the calcium carbonate fine powder coated with aluminum or silicon oxide, a binder such as a resin may be used in combination. The ratio of the binder to the calcium carbonate fine powder coated with aluminum or silicon oxide is 200% in terms of solid content in order to obtain ink absorbency.
Or less, and more preferably 100% or less. If the binder has a high binding force, the content is more preferably 50% or less. In order to secure the binding force, it is preferably at least 3%.
0% or more is more preferable.

Various resins and the like can be used as the binder, for example, PVA, polyvinylpyrrolidone, CMC,
Water-soluble resins such as hydroxyethylcellulose, casein, gelatin, starch and sodium alginate, further, vinyl acetate, vinyl chloride-vinyl acetate copolymer, styrene-butadiene copolymer, polyurethane, acrylic copolymer, maleic acid copolymer Emulsions of synthetic resins such as are used. These are appropriately selected, and an appropriate amount is used alone or in combination.

In order to fix an aqueous dye in an ink-jet ink, an ink containing a cationic component is useful. The binder may be cationic, and examples thereof include those in which an amine salt or an ammonium salt is bound to the resin or the like, or a component obtained by copolymerizing a component containing these functional groups.

[0017] Further, apart from the binder, a cationic component,
For example, a cationized polymer generally called a cationizing agent may be used in combination. In this case, the binder is desirably nonionic or cationic. This is because when an anionic binder and a cationizing agent are used in combination, resin aggregation is likely to occur. Examples of the cationizing agent include low molecular weight compounds such as long-chain alkylamine salts, long-chain alkyldimethylamine salts, long-chain alkyltrimethylammonium salts, allylamine or a salt thereof, diallyldimethylammonium salt, dialkylamino (meth) acrylate Either a homo- or copolymer of ethyl or a salt thereof, a trialkylammonium ethyl (meth) acrylate, diethylaminostyrene, or a copolymer with another monomer, a polyalkylene polyamine, a dicyandiamide resin, or the like may be used. it can. The amount used depends on the selected pigment, binder and their ratio, but is usually added in an amount of about 1 to 50% based on the pigment.

[0018] In addition to the above components of the pigment, binder and cationizing agent, various additives may be added to the ink receiving layer including a layer using calcium carbonate fine powder coated with aluminum or silicon oxide as required. An agent may be used. For example,
A surface conditioner, an antifoaming agent, a dispersant, a viscosity adjuster, a crosslinking agent, a coloring dye, a fungicide, a preservative, an antistatic agent, a lubricant, an antidusting agent, a water retention agent, and the like can be used.

The thickness of the ink receiving layer including the layer using calcium carbonate fine powder coated with aluminum or silicon oxide is generally preferably 1 μm to 100 μm, and if it is less than that, it is difficult to obtain printability with little bleeding. Above that, the portion of the lower portion of the ink receiving layer that does not contribute to ink reception increases, which unnecessarily increases the cost.

The ink receiving layer may have a layer structure of two or more layers, and a layer containing calcium carbonate fine powder coated with aluminum or silicon oxide may be used as a lower layer, an upper layer or an intermediate layer. For example, a layer containing calcium carbonate fine powder coated with aluminum or silicon oxide is used as a lower layer, and a layer that gives a specific texture to the surface such as glossiness is provided as an upper layer, or calcium carbonate coated with aluminum or silicon oxide is provided. A layer capable of obtaining higher quality printing than a layer containing fine powder may be provided as an upper layer.

The base material on which the ink receiving layer is provided is paper,
Any resin resin, cloth, or any other shape that can be printed by an inkjet printer can be used. Various layers may be provided between these base materials and the ink receiving layer as needed. For example, an easy adhesion layer, an antistatic layer, a coloring layer, a vapor deposition layer, and the like can be given.

The ink receiving layer may be provided on one side or both sides, and the ink receiving layer of the present invention may be provided on one side and a different ink receiving layer, antistatic layer and colored layer may be provided on the other side. An evaporation layer, an anti-curl layer, a layer for controlling slippage, a layer suitable for printing other than ink jet recording, a decoration layer, and the like may be provided as necessary.

The ink jet recording material of the present invention may be manufactured by any manufacturing method, and a typical example will be described below.

First, if necessary, a surface treatment or a lower layer is applied to the base material, and a coating machine known in the art, such as a blade coater, an air knife coater, a reverse coater, a bar coater, a gravure coater, a die coater, etc., is applied thereon. Containing the calcium carbonate fine powder coated with aluminum or silicon oxide and a binder, and wherein the binder is cationic or contains another cationic component, and other necessary components are contained. The dried coating composition is applied and dried. If necessary, the coated surface may be treated with a smoothing treatment machine, for example, a super calender, a gloss calender, a thermo punisher or the like to further improve smoothness.

Next, if necessary, at least one upper layer may be provided on a layer using calcium carbonate fine powder coated with aluminum or silicon oxide as a main component and also using a cationic component in combination. However, the layer must not impair the printability of ink jet recording. For example, a gloss layer, a layer capable of printing with higher definition, a protective layer, a UV absorbing layer, and the like can be provided.

[0026]

Next, the present invention will be described in detail with reference to Examples and Comparative Examples, which are intended to specifically explain the effects of the present invention, and are not intended to limit the present invention. is not.

Example 1 Callite SA (manufactured by Shiraishi Industry Co., Ltd .; calcium carbonate having an average particle size of 3.8 μm) was dispersed in isopropyl alcohol. To this dispersion, calcium carbonate is added with aluminum isopropoxide so that the monomolecular layer can be coated with aluminum oxide, and further water is added at 12 times the aluminum equivalent of aluminum isopropoxide added earlier. As a result, aluminum isopropoxide was hydrolyzed to deposit aluminum hydrated oxide on calcium carbonate. The dispersion was filtered and dried, and then subjected to a heat treatment to obtain calcium carbonate coated with aluminum oxide.

100 parts of calcium carbonate coated with the aluminum oxide 40 parts of Poval PVA-217 (manufactured by Kuraray Co., Ltd .; polyvinyl alcohol) 36 parts of PAS-H-10L (manufactured by Nitto Boseki; cationizing agent) 575 parts of water

The above composition was mixed and stirred to obtain a surface layer coating material A having a solid content of 20%. Obtained surface layer paint A
Was coated on a base paper for 85 g / m ² coated paper using a bar coater so that the coating amount after drying was 20 g / m ² , to obtain an ink jet recording material.

<Comparative Example 1> Carplex BS-304F (manufactured by Shionogi & Co., Ltd .; average particle size: 17%) was used in place of the calcium carbonate coated with the aluminum oxide of Example 1.
An ink jet recording material was produced in the same manner as in Example 1 except that 5 μm silica) was used.

<Comparative Example 2> Carplex BS-304F (manufactured by Shionogi & Co., Ltd .; average particle size: 17%) was used in place of the calcium carbonate coated with aluminum oxide of Example 1.
Ink jet recording was performed in the same manner as in Example 1 except that 5 parts of silica) and 2 parts of Tinopearl 25 (manufactured by Ciba Specialty Chemicals Co., Ltd .; diaminostilbene disulfonic acid derivative) were added as a fluorescent whitening agent. An agent was prepared.

Using the ink jet recording materials obtained in Example 1, Comparative Example 1 and Comparative Example 2 as test samples, each of the following measurement items was measured by the corresponding measurement method. Table 1 summarizes the results.

<Measurement Items and Test Methods> Printing characteristics Using a printer PM-2000C manufactured by Epson on the outermost surface, black (K), cyan (C), magenta (M), yellow (Y), C + M, M + Y C + Y solid was printed, and the following characteristics were evaluated. The ink absorption and drying properties were both good.

1-1 Print Density After 24 hours of printing, the density of the designated print portion (black) was measured by a Macbeth densitometer RD915.

2. Discoloration and discoloration The printed sample was irradiated with a xenon weatherometer for 24 hours, and the colors before and after were measured as L ^* , a ^* , b ^* values using a color difference meter, color-guide manufactured by BYK-Gardner, using the following formula. The discoloration degree ΔE was determined. The smaller the value, the smaller the discoloration of the image.

ΔE = [(ΔL ^* ) ² + (Δa ^* ) ² + (Δ
b ^* ) ² ] ^1/2

3. Whiteness The whiteness of the paper was measured with a Hunter reflectometer according to JIS P8123. The larger the value, the whiter the paper color.

[0038]

[Table 1]

As is apparent from the results of the above test, the quality of the ink jet recording material of the present invention in Example 1 is equal to or higher than that of Comparative Examples 1 and 2 in print density, It was found that the sample was very excellent and excellent in whiteness.

[0040]

As described above, according to the ink jet recording material of the present invention and the method for producing the same, it is possible to obtain an ink jet recording material with less discoloration of the print due to light or the like.

Claims (3)

[Claims] 1. An ink jet recording material having an ink receiving layer formed on at least one surface of a base material, wherein calcium carbonate fine powder coated with aluminum or silicon oxide as a main component of at least one of the ink receiving layers is provided. An ink-jet recording material, characterized in that the ink-jet recording material comprises a body and a cationic component as another component. 2. The calcium carbonate fine powder coated with aluminum or silicon oxide has a particle diameter of 1 to 20 μm.
m, BET specific surface area is 200 m ² / g or less, oil absorption is 20
2. The ink jet recording material according to claim 1, wherein the amount is 0 to 1000 ml / 100 g. 3. A method for producing an ink jet recording material base material having an ink receiving layer on at least one surface of a base material, wherein at least one surface of the base material or the base material provided with an underlayer is provided. Applying and drying a paint containing calcium carbonate fine powder coated with aluminum or silicon oxide and a binder, wherein the binder is cationic or also contains another cationic component A method for producing an ink jet recording material, comprising: