JP2000247019A - Medium to be recorded for ink-jet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To impart good ink absorbability, ink fixing properties, water resistance and blending resistance to a medium to be ink jet recorded which is provided with a dye fixing layer formed of an interlaminar compound acceptively retaining a water-soluble dye by the intercalation reaction and a binding agent and form and retain a sharper image. SOLUTION: A medium to be ink-jet recorded is composed of a dye fixing layer 1 formed of an interlaminar compound acceptively holding a water-soluble dye by the intercalation reaction and an binding agent and formed on a base 2. In that case, a polyvinyl alcohol resin modified by a carboxyl and an epoxy is used as the binding agent.

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]

Means for Solving the Problems The present inventors use a polyvinyl alcohol resin modified with a carboxyl group and an epoxy group as a binder for a dye fixing layer located on the surface of an ink jet recording medium. As a result, the present inventors have found that the above object 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 polyvinyl alcohol resin modified with a carboxyl group and an epoxy group.

[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 polyvinyl alcohol resin modified with a carboxyl group and an epoxy group. . 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 polyvinyl alcohol resin modified with a carboxyl group and an epoxy group used in the present invention includes a compound having an epoxy group bonded to a vinyl group, a compound having a carboxyl group bonded to a vinyl group, It corresponds to a copolymer with vinyl alcohol. Here, when the total content of the carboxyl group and the epoxy group with respect to 100 parts by weight of vinyl alcohol is too small, it is difficult to maintain sufficient water resistance, and when it is too large, the ink permeability becomes insufficient. Is 1
10 parts by weight.

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

In the present invention, when the weight ratio of the intercalation compound and 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 contained in the dye fixing layer 1 is a layered inorganic polymer having a layered structure and having an exchangeable anion capable of ion exchange with a water-soluble dye between its hydrophilic layers. Preferred examples can be given.

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 AlO ₆ octahedral sheet. Preferred examples include layered hydrotalcite group minerals. Preferred hydrotalcite group minerals include those represented by formula (1) or (2)

[0019]

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. )

[0020]

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.) Formula (3) is a typical example of hydrotalcite minerals.

[0021]

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 that of the 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-mentioned hydrotalcite group minerals, as anion-exchangeable intercalation compounds, there are hydrated oxides such as titanium, zirconium, lanthanum, bismuth and the like, and phosphate hydroxides. 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 further 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 40 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 transfers 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 the thickness is too large, 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 recording 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 ink jet recording medium of the present invention comprises:
It can be used in the same manner as a conventional inkjet recording medium.

[0034]

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

Examples 1-4 In a mixed solvent of 8 g of isopropyl alcohol and 72 g of water, carboxyl groups and epoxy groups were modified as binders in the proportions shown in Table 1 (% by weight based on the modified polyvinyl alcohol resin). 10 g of polyvinyl alcohol resin,
Organic acid treated hydrotalcite 10g as interlayer compound
(10 g of hydrotalcite subjected to an adsorption treatment of 10 mg of malic acid) and treated with a bead mill for 8 hours to obtain a dispersion. The resulting dispersion was applied to a 100 μm-thick easily-adhesive transparent polyester film (D-535, manufactured by ICI) with a wire bar so as to have a dry thickness of 8 μm, dried at 90 ° C. for 2 minutes and dried. By forming a fixing layer, a recording medium for inkjet was obtained.

Comparative Example 1 An ink jet recording medium was obtained in the same manner as in Example 1 except that an unmodified polyvinyl alcohol resin was used instead of the polyvinyl alcohol resin modified with a carboxyl group and an epoxy group.

Examples 5 to 8 A gelatin resin (manufactured by Miyagi Chemical Industry Co., Ltd .: E-29) was formed on the dye fixing layer of the ink jet recording medium of Examples 1 to 4.
0) was applied to a dry thickness of 0.8 μm,
The ink-absorbing layer was formed by drying under the condition of a minute to obtain an inkjet recording medium.

Comparative Example 2 An inkjet recording medium was obtained in the same manner as in Example 5, except that an unmodified polyvinyl alcohol resin was used instead of the polyvinyl alcohol resin modified with a carboxyl group and an epoxy group.

(Evaluation) A test pattern image was formed on the obtained ink-jet recording medium with an ink-jet recording system printer (HP850C, manufactured by Hewlett-Packard Company), and “ink absorption” and “ink fixing property ( ) Was 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 the ink droplets having been ink-jetted penetrate into the recording medium for ink-jetting and were absorbed was visually observed and evaluated.

Ink Fixing Property The recording medium for inkjet on which the test pattern image was printed was immersed in water for 10 minutes, and the blur of the test pattern image was visually observed and evaluated.

[0042]

[Table 1]

From the results of Examples 1 to 4 and Comparative Example 1 in Table 1, when a polyvinyl alcohol resin modified with a carboxyl group and an epoxy group is used as a binder for a dye fixing layer of an ink jet recording medium, It can be seen that the ink absorbency and the ink fixability are excellent.

From the results of Examples 5 to 8 and Comparative Example 2, even if an ink absorbing layer was further provided on the dye fixing layer using a polyvinyl alcohol resin modified with a carboxyl group and an epoxy group, It can be seen that good results can be obtained for both the items of ink absorbency and ink fixability.

[0045]

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

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yasuhiro Tanaka 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo F-term in Sony Corporation (reference) 2C056 EA13 FC06 2H086 BA16 BA31 BA35 4F100 AA00B AC10B AK21B AL06B AR00C AT00A BA03 BA07 BA10A BA10C JB07 JD14C 4J002 BE021 CD191 DE096 DE136 DE286 DH046 FB076 FB086 FB236 FB246 FB296 FD020 FD050 FD140 FD200 FD206 GS00 HA08

Claims (5)

[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 polyvinyl alcohol resin modified with a carboxyl group and an epoxy group. 2. An ink jet recording medium according to claim 1, wherein at least one ink absorbing layer made of an ink absorbing resin is formed on said dye fixing layer. 3. The ink jet recording medium according to claim 1, wherein the intercalation compound is a layered inorganic polymer having exchangeable anions. 4. The ink jet recording medium according to claim 1, wherein the layered inorganic polymer having exchangeable anions is a hydrotalcite group mineral. 5. 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 inkjet recording medium according to claim 4, which is a positive number that satisfies the following.