JP2000296664A - Recording media for inkjet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide good ink absorption to an ink jet recording medium having a dye fixing layer formed of a binder and an interlayer compound which receives and holds a water-soluble dye by an intercalation reaction. It imparts properties, ink fixing properties, water resistance and bleeding resistance, and can maintain a clearer image. SOLUTION: In a recording medium for ink-jet recording comprising a dye fixing layer 1 comprising a binder and an interlayer compound for receiving and holding a water-soluble dye by an intercalation reaction on a base material 2, the binder Used is a quaternary ammonium-modified polyvinyl alcohol resin.

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 medium having a dye fixing layer containing an intercalation compound which receives and retains a water-soluble dye in an aqueous ink jet ink by an intercalation reaction.

[0002]

2. Description of the Related Art Image information and character code information produced by a personal computer or a word processor are
One of the methods for outputting to a recording medium such as paper or an OHP film is to apply an ink containing a water-soluble dye to an electric field, heat,
There is an ink jet recording method in which an image is formed by discharging a recording medium using a pressure or the like as a driving source from a recording nozzle to a recording medium.

[0003] This ink jet recording system has the advantages of low noise at the time of recording, low running cost, image formation on plain paper, and the absence of waste such as ink ribbon. In homes and homes, its use has been expanding in recent years.

[0004] Ink-jet recording media used in such an ink-jet recording system include an interlayer compound capable of holding a water-soluble dye by an intercalation reaction in a dye fixing layer of the recording medium, a polyvinylpyrrolidone resin, It has been proposed to mix with a binder such as a polyvinyl butyral resin, a hydroxypropyl cellulose resin or a polyvinyl alcohol resin (JP-A-7-68925).

[0005]

However, when the above-mentioned binder is used, the fixing property of the ink on the recording medium for ink jet, fading and discoloration during storage, and the like.
Although improvements have been seen with respect to the reduction in printing density and the like, ink absorption and water resistance have been insufficient. In particular, in areas where ink droplets have adhered at a high density, the ink droplets have been applied to an inkjet recording medium (printing medium). Before being absorbed by the ink-receiving layer (dye-fixing layer) of the paper), causing a problem that the resolution is reduced.

An object of the present invention is to solve the above-mentioned problems of the prior art. In the present invention, a dye fixing layer comprising a binder and an interlayer compound for receiving and retaining a water-soluble dye by an intercalation reaction is formed. It is an object of the present invention to impart good ink absorbency, ink fixing property, water resistance and bleeding resistance to a recording medium for ink jet recording, and to maintain a clearer image.

[0007]

The present inventors have achieved the above object by using a quaternary ammonium-modified polyvinyl alcohol resin as a binder for a dye fixing layer located on the surface of an ink jet recording medium. They have found that this can be achieved, and have completed the present invention.

That is, the present invention relates to a recording medium for ink-jet recording comprising a dye fixing layer comprising a binder and an interlayer compound for receiving and retaining a water-soluble dye by an intercalation reaction on a substrate. Provided is a recording medium for inkjet, wherein the binder contains a quaternary ammonium-modified polyvinyl alcohol resin.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

FIGS. 1 and 2 are cross-sectional views of an ink jet recording medium according to a preferred embodiment of the present invention.

The recording medium for ink jet recording shown in FIG. 1 has a structure in which a dye fixing layer 1 is formed on a base material 2 in which an interlayer compound for receiving and holding a water-soluble dye by an intercalation reaction is dispersed in a binder. It has become.

The ink-jet recording medium shown in FIG. 2 is, similarly to the embodiment of FIG. 1, dye-fixed by dispersing an interlayer compound which receives and retains a water-soluble dye by an intercalation reaction in a binder. A layer 1 is formed on a substrate 2;
Further, an ink absorbing layer 3 made of an ink absorbing resin is further formed thereon.
Is formed.

In the present invention, in both of the embodiments of FIGS. 1 and 2, the binder of the dye fixing layer 1 of the recording medium for ink jet contains a quaternary ammonium-modified polyvinyl alcohol resin. This makes it possible to impart good ink absorbency, ink fixability, water resistance and bleeding resistance to the recording medium for ink jet, and to maintain a clearer image.

The quaternary ammonium-modified polyvinyl alcohol resin used in the present invention includes a polymer having a structure in which a quaternary ammonium residue is bonded to a polyvinyl alcohol main chain. Such a quaternary ammonium-modified polyvinyl alcohol resin can be produced by copolymerizing a vinyl acetate monomer and a quaternary ammonium residue-containing monomer copolymerizable therewith, and saponifying it.

If the quaternary ammonium-modified polyvinyl alcohol resin used in the present invention has a quaternary ammonium modification ratio (= 100 × {mol number of quaternary ammonium-containing monomer} / {mol number of vinyl alcohol}), polyvinyl alcohol resin is too low. The properties of the alcohol resin are dominant and the ink fixability tends to be insufficient. If the property is too high, the quaternary ammonium-modified polyvinyl alcohol resin becomes sticky and the commercial value is greatly reduced.
ol%.

In the present invention, all of the binder of the dye fixing layer 1 may be composed of a quaternary ammonium-modified polyvinyl alcohol resin, and if necessary, a normal binder may be used as long as the effects of the present invention are not impaired. Agents (eg, aqueous polyurethane emulsion resin, polyvinylpyrrolidone resin,
Hydroxypropyl alcohol resin, hydroxypropyl methylcellulose resin, polyvinyl alcohol resin,
Organic resins such as ethyl cellulose resin and gelatin).

In the present invention, the dye fixing layer 1 may contain various additives (for example, a crosslinking agent, a plasticizer, an ultraviolet absorber, a fluorescent whitening agent, etc.) used in the conventional dye fixing layer, if necessary. Hydrophilic resins, dispersion resins, emulsion resins, etc.).

In the present invention, when the weight ratio of the intercalation compound to the binder in the dye fixing layer 1 is too small, the amount of the water-soluble dye retained by the intercalation reaction is reduced if the intercalation reaction is too small. When the amount is too large, the amount of the binder is relatively reduced, and the adhesiveness and dispersibility of the dye fixing layer 1 are reduced. 1: 8, more preferably 1: 0.2 to 1:
1.5.

In the present invention, the interlayer compound to be contained in the dye fixing layer 1 is preferably a layered inorganic polymer having a layered structure and having exchangeable ions capable of ion exchange with a water-soluble dye between its hydrophilic layers. Examples can be given.
Here, the exchangeable ion of the layered inorganic polymer is an exchangeable cation such as a sodium ion when the water-soluble dye is a cationic dye, and a carboxyl when the water-soluble dye is an anion dye. An exchangeable anion such as an anion, and the latter is generally preferred.

The layered inorganic polymer having exchangeable anions (hereinafter referred to as anion-exchange intercalation compound) used in the present invention is a kind of 0: 1 type clay mineral and is composed of an AlO ₆ octahedral sheet. A layered hydrotalcite group mineral is preferably exemplified. Preferred hydrotalcite group minerals include those represented by formula (1) or (2)

[0021]

Embedded image [MII _1-x MIII _x (OH) ₂ ] ^{+ x} [A _{x / n} · mH ₂ O] ^−x (1) (wherein, MII is a divalent material such as Mg, Zn, Ni, Ca, etc.) MIII represents a trivalent metal ion such as Al, and A represents n
X and m represent 0.1 <x <0.4,
It is a positive number satisfying 0 <m <2. )

[0022]

Embedded image [LiAl ₂ (OH) ₆ ] ⁺¹ [A _{1 / n} · mH ₂ O] ⁻¹ (2) (where A represents an n-valent anion, and m represents 0 <m <2) Is a positive number that satisfies.) As a typical example of the hadrothalcite group mineral, the formula (3)

[0023]

Embedded image A natural hydrotalcite represented by Mg ₆ Al ₂ (OH) ₁₆ .CO ₃ .4H ₂ O (3) can be exemplified.

Although the composition is slightly different from the composition of natural hydrotalcite of the formula (3), synthetic hydrotalcite is also commercially available. Although the fine powder of this synthetic hydrotalcite does not contain impurities and presents a pure white color, the crystal itself is optically transparent.
It is possible to form the dye fixing layer 1 which realizes high saturation comparable to silver halide photography.

In addition to the above hydrotalcite group minerals, as anion-exchangeable intercalation compounds, there are hydrated oxides such as titanium, zirconium, lanthanum, bismuth and the like, and hydroxide phosphates. Since it has a hiding property or a unique color, it can be used when transparency, glossiness and whiteness are not simultaneously required for the dye fixing layer 1.

The exchangeable anions to be present between the layers of the anion exchangeable intercalation compound used in the present invention include inorganic anions which are easily solvated in a high dielectric constant medium such as water or alcohol.
For example, NO ₃ ⁻ , SO ₄ ²⁻ , ClO ₄ ⁻ , Fe (CN) ₆ ⁴⁻ , a heteropolyphosphate ion or a hydrophilic organic anion such as a lower carboxylate ion can be used.
Note that higher carboxylate ions tend to provide interlayers that are more difficult to solvate than the aforementioned anions.

In order to improve the dispersibility of the anion-exchangeable intercalation compound in the binder and to improve the swelling of the anion-exchangeable intercalation compound in a non-aqueous solvent such as alcohol, one of the exchangeable inorganic anions of the anion-exchangeable intercalation compound is improved. The portion may be replaced with an organic anion that achieves the effect of increasing the interlayer distance (pillar effect) or the effect of partially hydrophobizing the interlayer. Examples of such an organic anion include a carboxylate anion, a sulfonate anion, an ester anion, and a phosphate anion.

Such an organic anion usually has an alkyl group or an alkenyl group, but when the number of carbon atoms is small, the pillar effect is not sufficient, and the interlayer as a fixing seat (= exchangeable inorganic anion) is used. Is difficult to secure. Further, if the amount is too large, substitution becomes difficult, and therefore, it is preferable that the carbon number thereof is 5 to 20.

The thickness of the dye fixing layer 1 is usually 2 to 4
0 μm, preferably 4 to 15 μm.

In the recording medium for ink jet recording of the present invention, the substrate 2 can be arbitrarily selected from paper, synthetic paper, plastic paper, metal plate, metal foil, plastic film on which aluminum or the like is deposited, and organic resin and the like. A substrate which has been subjected to a treatment for easy adhesion can also be used. In addition, it is necessary that the film is light-transmitting for applications such as an OHP film.

The ink absorbing layer 3 of the ink jet recording medium of the present invention shown in FIG. 2 temporarily receives the attached ink and transmits it to the dye fixing layer 1.

Examples of the ink-absorbing resin constituting the ink-absorbing layer 3 include cellulose resins (for example, hydroxypropylcellulose resin, methylcellulose), polyvinyl alcohol resin, gelatin, hydratable polyvinyl acetal resin, polyvinylpyrrolidone resin and the like. .

The thickness of the ink absorbing layer 3 is usually 5 μm or less, preferably 3 μm or less, because if it is too thick, the ratio of the dye fixed to the dye fixing layer 1 decreases and the dye fixing property deteriorates.

The recording medium for ink jet of the present invention can be produced by a conventional method. For example, it can be produced by dispersing an interlayer compound and a binder in a solvent, applying the dispersion on the base material 2 and drying. When the silicone oil is contained in the dye fixing layer 1, the silicone oil is added to the dispersion and applied. Further, when the ink absorbing layer 3 is required, it can be produced by adding silicone oil to the ink absorbing resin, applying the silicone oil on the dye fixing layer 1, and drying.

The recording medium for ink jet recording of the present invention comprises:
It can be used in the same manner as a conventional inkjet recording medium.

[0036]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments.

Example 1 In a mixed solvent of 8 g of isopropyl alcohol and 72 g of water, a quaternary ammonium-modified polyvinyl alcohol resin having a quaternary ammonium modification rate shown in Table 1 was used as a binder.
g, hydrotalcite 1 treated with organic acid as an interlayer compound
After adding 0 g (10 g of hydrotalcite to malic acid 10 mg equivalent adsorption treatment), the mixture was treated with a bead mill for 8 hours to obtain a dispersion. The obtained dispersion was dried to a thickness of 8 μm.
The test was conducted by applying a 100 μm thick transparent polyester film (manufactured by ICI: D-535) having a thickness of 100 μm with a wire bar and drying at 90 ° C. for 2 minutes to form a dye fixing layer. Ink-jet recording media of Examples 1 to 8 were obtained. However, in Experimental Example 1, an unmodified polyvinyl alcohol resin was used.

Example 2 In the same manner as in Example 1, a quaternary ammonium-modified polyvinyl alcohol resin having a quaternary ammonium modification rate shown in Table 1 was used to form a 100 μm-thick easily-adhesive transparent polyester film having a dry thickness of 8 μm. A dye fixing layer was formed.

Next, a gelatin resin (manufactured by Miyagi Kagaku Kogyo KK: E-290) was dried on the dye fixing layer at a dry thickness of 0.8 μm.
And dried at 90 ° C. for 1 minute to form an ink absorbing layer, thereby obtaining inkjet recording media of Examples 9 to 13.

(Evaluation) A test pattern image was formed on the obtained ink-jet recording medium using an ink-jet recording system printer (HP850C, manufactured by Hewlett-Packard Company), and “ink absorption” and “ink fixability” were measured. And "bleeding resistance" were tested and evaluated as described below. In addition, the evaluation result was ranked as "O" for a good test item, "X" for a bad test item, and "、" for the middle of the test items. Table 1 shows the obtained results.

Ink Absorbability Whether or not ink jet ink droplets permeated the ink jet recording medium and were absorbed was visually observed and evaluated.

Ink Fixing Property The recording medium for ink jet on which the test pattern image was printed was immersed in water for 10 minutes, and the bleeding of the test pattern image was visually observed to evaluate the ink fixing property.

The recording medium for ink jet printing on which the bleeding resistance test pattern image was printed was subjected to 24 hours at a temperature of 60 ° C. and a humidity of 85%.
After leaving for a while, the blur of the test pattern image was visually observed and evaluated.

[0044]

[Table 1] Quaternary ammonium-modified polyvinyl alcohol resin Quaternary ammonium modification ratio (mol%) Ink absorption Ink fixability Bleed resistance (Example 1 (without ink absorption layer)) Experimental example 10 ○ × ○ 21 1 ○ ○ ○ 33 ○ ○ ５ 45 ○ ○ ○ 510 ○ ○ 620 ○ ○ ７ 722 ○ × ８ 825 ○ × （(Example 2 (with ink-absorbing layer)) ○ 11 10 ○ ○ ○ 12 15 ○ ○ ○ 13 20 ○ ○ ○

Experimental Example 1 (quaternary ammonium modification ratio = 0 mol%) and Experimental Example 2 (quaternary ammonium modification ratio =
1 mol%), the use of a quaternary ammonium-modified polyvinyl alcohol resin as a binder for the dye fixing layer of the recording medium for ink-jet recording enables the ink absorption and bleeding resistance to be maintained in a favorable state, It can be seen that the ink fixability can be improved. Also, from the results of Experimental Examples 2 to 8, the preferable range of the quaternary ammonium modification rate is 1 to 2
It turns out that it is 0 mol%.

From the results of Experimental Examples 9 to 13, even if an ink absorbing layer is further provided on the dye fixing layer using the quaternary ammonium-modified polyvinyl alcohol resin, the ink absorbing property, the ink fixing property, and the resistance to ink are improved. It can be seen that good results can be obtained for all items of bleeding.

[0047]

The recording medium for ink jet recording of the present invention is excellent in ink absorbency, fixability, water resistance and bleeding resistance, so that a clear image can be maintained.

[Brief description of the drawings]

FIG. 1 is a sectional view of an inkjet recording medium of the present invention.

FIG. 2 is a sectional view of an inkjet recording medium of the present invention.

[Explanation of symbols]

 1: Dye fixing layer, 2: Base material, 3: Ink absorption layer

Continued on the front page (72) Inventor Hiroko Numayama 6-35 Kita Shinagawa, Shinagawa-ku, Tokyo Sony Corporation F-term (reference) 2H086 BA15 BA31 BA34

Claims (6)

[Claims] 1. An ink jet recording medium comprising a substrate and a dye fixing layer comprising a binder and an interlayer compound for receiving and holding a water-soluble dye by an intercalation reaction, wherein the binder is Contains a quaternary ammonium-modified polyvinyl alcohol resin. 2. The quaternary ammonium-modified polyvinyl alcohol resin has a quaternary ammonium modification rate of 1 to 20 m.
2. The recording medium for ink jet recording according to claim 1, wherein the content is ol%. 3. The ink jet recording medium according to claim 1, wherein at least one ink absorbing layer made of an ink absorbing resin is formed on the dye fixing layer. 4. The ink jet recording medium according to claim 1, wherein the interlayer compound is a layered inorganic polymer having exchangeable anions. 5. The ink-jet recording medium according to claim 1, wherein the layered inorganic polymer having exchangeable anions is a hydrotalcite group mineral. 6. The hydrotalcite group mineral represented by the formula (1) or (2): [MII _1-x MIII _x (OH) ₂ ] ^{+ x} [A _{x / n} · mH ₂ O] ^-x ( 1) (wherein, MII represents a divalent metal ion, MIII represents a trivalent metal ion, A represents an n-valent anion, and x and m are each 0. 1).
It is a positive number satisfying 1 <x <0.4 and 0 <m <2. Embedded image [LiAl ₂ (OH) ₆ ] ⁺¹ [A _{1 / n} · mH ₂ O] ⁻¹ (2) (where A represents an n-valent anion, and m represents 0 <m <2) The recording medium for ink jet according to claim 5, wherein the recording medium is a positive number satisfying the following.