JPH08258410A - Ink-jet recording material - Google Patents

Abstract

PURPOSE: To improve ink absorption and an antiblocking property by using a support for an ink-jet recording material in which paper is laminated at least on one side of a plastic film and laminating an ink receiving layer on the paper of the support. CONSTITUTION: In a recording material used for ink-jet recording, a support is prepared by laminating paper at least on one side of a plastic film, and an ink receiving layer containing a complex of a water soluble resin and a metal salt is formed at least on one paper surface of the support. Here upon, polyvinyl alcohol is used as the water soluble resin, and the metal salt of 0.1-30mole% of the hydroxyl group of polyvinyl alcohol is incorporated. Or, polyvinyl pyrrolidone is used as the water soluble resin, and the metal salt of 10-200wt.% of polyvinyl pyrrolidone is incorporated. Calcium chloride is used preferably as the metal salt.

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 excellent in ink absorbency, resolution and water resistance and can also provide a display product having a surface gloss, if necessary. The present invention relates to an inkjet recording material having improved antiblocking property.

[0002]

2. Description of the Related Art Ink-jet recording methods use various ink (recording liquid) ejection methods to generate and fly small ink droplets, some or all of which adhere to a recording material such as paper for recording. The operation noise is low, high-speed printing and multicolor recording can be performed.

As the ink for ink jet recording, a water-based ink mainly containing water is used from the viewpoint of safety and recording characteristics, and these inks are used to prevent clogging of ink passages and ink ejection ports of an ink jet recording apparatus. Polyhydric alcohols are often added to improve the ejection stability.

As a recording material used for this ink jet recording, conventionally, a paper having a structure in which an ink receiving layer is provided on ordinary paper or various base materials has been used, but the performance of the recording apparatus is improved. With the increase in recording speed, the use of multiple colors, and the widespread use of recording devices, higher-performance recording materials are required.

Generally, when a color image is printed, the amount of ink absorbed per unit area is large, so that the recording material is wavy due to the swelling of the substrate, the ink drying and fixing time becomes long, and the ink cannot be completely absorbed. Problems such as, occur.

Therefore, it is conceivable to use a plastic film as a base material to prevent waviness and to thicken the ink receiving layer in order to improve ink absorption. However, in general, when the ink is absorbed or the recording material is placed in a place with high humidity or in a dry place, the ink receiving layer tends to expand, contract, etc., and curl occurs. Tends to get worse and worse. Therefore, from the viewpoint of preventing curling, an ink receiving layer is required that absorbs ink quickly even when formed thin and has good fixing and image quality, or is hard to curl.

The inventors of the present invention have previously proposed, as an ink jet recording material satisfying such performance, a technique of containing a complex of a water-soluble resin and a metal salt in the ink receiving layer (Japanese Patent Application No. 6-300385). issue). According to this technique, the ink absorptivity, the sharpness of the recorded image, the surface glossiness, and the curling prevention property are improved, and an inkjet recording material suitable for full-color recording can be obtained.
Further, although the antiblocking property can be improved as compared with the conventional product, the blocking still occurs, and in reality, the blocking is prevented by adding a large amount of the pigment.

[0008]

DISCLOSURE OF THE INVENTION The object of the present invention is excellent in ink absorbency, sharpness of recorded image, surface gloss as required, curling and waviness hardly occur, and full color recording is possible. Another object is to provide an ink jet recording material which, in addition to the performance that can be suitably used, further improves ink absorbency and is less likely to cause blocking without mixing a large amount of pigment.

[0009]

The ink jet recording material of the present invention that can achieve the above object is a water-soluble resin on at least one paper surface of a support in which paper is bonded to at least one surface of a plastic film. And an ink receiving layer containing a complex of a metal salt.

The present invention will be described in detail below.

As the support of the present invention, a support obtained by sticking paper to one side or both sides of a plastic film is used.

Examples of the plastic film used for the support include films made of polyester, polycarbonate, cellulose acetate, polyimide, polyethylene, polystyrene, polypropylene and the like.

As the paper to be attached to one side or both sides of the plastic film, either Japanese paper or Western paper can be used. The raw materials for Japanese paper are swordfish, hemp, Japanese camellia, and geese.
Moreover, wood pulp, synthetic pulp, etc. can be used as a raw material of the foreign paper, and the thickness is 6 to 29 g / m ² , preferably 9 to 15
Those of g / m ² are suitable for the present invention.

When Japanese paper or foreign paper is attached to a plastic film, an adhesive is usually used. Examples of the adhesive used include urea-based, phenol-based, resorcinol-based, epoxy-based, urethane-based, polyester-based,
Examples of the adhesive include isocyanate-based, vinyl acetate-based, acrylic-based, cyanoacrylate-based, copolymer nylon-based, and modified rubber-based adhesives.

According to the present invention, since such a support is used, the paper is absorbed even if an amount of ink that cannot be absorbed by the ink receiving layer is ejected, and as a result, the thickness of the entire ink receiving layer and the recording material. The anti-blocking property can be greatly improved in combination with the specific ink receiving layer described later. Further, unlike the conventional recording material using paper as a base material, the paper does not swell due to absorption of ink and cause waviness.

Next, the ink receiving layer used in the recording material of the present invention uses a complex of a water-soluble resin metal salt as a binder of the ink receiving layer.

Examples of the water-soluble resin include polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid and the like. Among these, polyvinyl alcohol is preferable, and the saponification degree is 85 mol% or more, preferably 90%.
It is preferably at least mol%, most preferably at least 98 mol%. The higher the degree of saponification, the higher the degree of saponification. When it is 85 mol% or more, when a complex with a metal salt is formed, the film has good coatability and is not sticky, and the ink receiving performance such as the drying speed of ink and the quality of recorded images are good. Therefore, it is preferable. When the degree of polymerization is 10 or more, preferably 100 or more, and most preferably 500 or more, the coating property and the like are good, and it is easy to handle in terms of fluidity of the solution. The degree of polymerization of 100,000 or less, preferably 10,000 or less, and most preferably 2000 or less is easy to handle in terms of fluidity of the solution.

It is also preferable to use polyvinylpyrrolidone as the water-soluble resin. When the ink receiving layer is applied onto the paper layer, if water is applied as a solvent, curling may occur and the coating workability may decrease. In this case, if polyvinylpyrrolidone is used as the water-soluble resin, the solvent can be coated with a solvent such as alcohol or cellosolve, so that the deterioration of coating workability can be prevented.

Other resins may be added to the ink receiving layer to the extent that the original intended performance is not impaired. Such resins include, for example, polyacrylamide, polyvinyl acetate, acrylic ester, cellulose, hydroxycellulose, alkyl cellulose, gelatin, chitin, chitosan, starch and the like.

The metal salt which forms a complex with the water-soluble resin is calcium ion, iron ion, aluminum ion, magnesium ion, chromium ion, cobalt ion, cadmium ion, zinc ion, nickel ion, lithium ion as the constituent metal ions. Etc., but
Examples of metal salts that give these metal ions include calcium chloride, zinc chloride, aluminum nitrate, aluminum chloride,
It is preferable to use one or more kinds of cobalt chloride, cadmium chloride, magnesium chloride, cadmium nitrate, and their double hydrates. However, the metal salts are not limited to the above metal salts, and chlorides other than the above metal salts, nitrates, acetates, sulfates, and other salts can be used as long as they are salts of the above metal ions. Among the above metal salts, particularly excellent calcium receptivity and recorded images can be obtained by using calcium chloride or its double hydrate.

Generally, as the mixing ratio of the metal salt to the water-soluble resin becomes higher, higher hygroscopicity can be obtained and curling becomes difficult, but as the mixing ratio becomes higher, the water-soluble resin of the metal salt becomes higher. Since the solubility of the metal ion in the solvent is reduced, the metal ion cannot be highly dispersed, and as a result, the contact area between the metal ions is widened, and the hydration effect of the metal ion is reduced, so that the hygroscopicity is deteriorated in the initial stage. May result. Further, if the hygroscopicity becomes too high, the humidity in the air is absorbed, resulting in stickiness of the surface of the receiving portion when used as an ink receiving layer. Further, even if the stickiness does not occur to that extent, it may cause blocking. On the contrary, when the mixing ratio of the metal salt is low, the amount of metal ions is small, so that the hygroscopic ability is deteriorated, the ink receiving performance is deteriorated, and the curling is easy.

Therefore, a suitable mixing ratio of the metal salt exists depending on the kinds of the metal salt and the water-soluble resin. When polyvinyl alcohol is used as the water-soluble resin and calcium chloride is used as the metal salt, the amount is 0.01 mol% or more, preferably 0.1 mol% or more, and most preferably 5 mol% or more with respect to the hydroxyl group of polyvinyl alcohol. By mixing, the ink receiving performance can be satisfied and curling can be suppressed. In addition, 80 mol% or less, preferably 30 mol% or less, relative to the hydroxyl group of polyvinyl alcohol,
Most preferably, by mixing 15 mol% or less, stickiness on the surface can be suppressed.

When polyvinylpyrrolidone is used as the water-soluble resin and calcium chloride dihydrate is used as the metal salt, 10% by weight or more, preferably 40% by weight or more, of dihydrate of calcium chloride is used with respect to polyvinylpyrrolidone. ,
Most preferably, by mixing 60% by weight or more, the ink receiving performance can be satisfied and curling can be suppressed. Further, the stickiness of the surface can be suppressed by mixing calcium dihydrate of 200% by weight or less, preferably 120% by weight or less, and most preferably 100% by weight or less with respect to polyvinylpyrrolidone.

The metal salt is not limited to one kind, and two or more kinds may be mixed if necessary. By mixing a plurality of metal salts, it becomes easy to adjust stickiness and ink receiving performance.

In addition to the above substances, an antioxidant, an ultraviolet absorber, a surfactant, etc. may be added to the ink receiving layer to the extent that the performance as the ink receiving layer is not impaired.

It is also effective to add a pigment for the purpose of further improving antiblocking property and ink receptivity. As the pigment, pigments used in ordinary ink jet recording materials, for example, silica, titanium oxide, zinc oxide, calcium carbonate, barium sulfate, resin particles, mica,
Montmorillonite etc. can be used. In the present invention, the complex of the water-soluble resin metal salt is used as the binder of the ink receiving layer and is provided on the paper layer, so that the ink receiving property can be satisfied without adding a large amount of pigment as in the conventional case. However, the glossiness of the surface can be increased by this.

The amount of the ink receiving layer provided on the paper layer of the support is preferably about 0.1 to 10.0 g / m ² , more preferably about 0.5 to 3.0 g / m ^2. . Within this range, the ink receptivity and the blocking prevention property are further improved.

Further, when the paper is attached to only one surface of the plastic film, or when the ink receiving layer is provided on only one surface of the support, the ink of the support is formed on the surface opposite to the paper of the plastic film. It is effective to provide a back coat layer on the opposite surface of the receiving layer for reducing the degree of curling and for smoothness.

[0029]

In the ink jet recording material of the present invention, a paper having a plastic film laminated on one side is used as a support, and a specific ink receiving layer is provided on this paper layer. Therefore, the plastic film alone is used as a support. The ink receptivity and antiblocking property are further improved as compared with the case where a specific ink receptive layer is provided on the layer.

[0030]

【Example】

(Example 1) An acrylic resin emulsion type adhesive was applied to both sides of a transparent polyester film having a thickness of 25 μm by a roll coater so as to be 3 g / m ^2, and after drying, 13 g / m ² of Japanese paper was applied to both sides. Together, a support was prepared.

Next, polyvinyl alcohol [Gothenol GL-05: manufactured by Nippon Synthetic Chemical Industry Co., Ltd.] was dissolved in water to give 10
% Solution was adjusted, there 30 mol% of calcium chloride [CaCl _2] as a metal salt, a zinc chloride [ZnCl _2] were mixed 10 mol%, and stirred at room temperature for about 1 day, the coating the ink receiving layer The liquid was adjusted.

The above coating liquid for the ink receiving layer was coated on one surface of the support with a bar coater and dried to give a dry adhesion amount of 1.0 g.
An inkjet recording material having an ink receiving layer of / m ² was prepared.

The ink jet recording material was printed in full color using an ink jet printer (DeskWriter550C: manufactured by Hewlett Packard), and the results of evaluation of bleeding characteristics, curling characteristics and drying characteristics are shown in Table 1.
Shown in The blocking resistance of the recording material before printing was also evaluated.

(Example 2) Carboxyl-modified polyvinyl alcohol [Gothenal T: manufactured by Nippon Synthetic Chemical Industry Co., Ltd.]
Is dissolved in water to prepare a 10% solution, and 50 mol% of calcium chloride [CaCl ₂ ] as a metal salt is mixed therein, and about 1
The coating solution for the ink receiving layer was prepared by stirring the mixture at room temperature on the day.

On one surface of the support obtained in Example 1, the above-mentioned coating liquid for ink receiving layer was applied by a bar coater and dried,
An inkjet recording material having an ink receiving layer having a dry deposition amount of 1.0 g / m ² was prepared.

The results of evaluation of this ink jet recording material in the same manner as in Example 1 are shown in Table 1.

Example 3 Polyvinylpyrrolidone [K-
90: manufactured by ISP] is dissolved in methyl alcohol to give 10
% Solution, mixed with calcium chloride dihydrate [CaCl ₂ .2H ₂ O] as a metal salt in an amount of 80% by weight based on the solid content of polyvinylpyrrolidone, and stirred at room temperature for about 1 day to prepare an ink. A coating liquid for the receiving layer was prepared.

On one surface of the support obtained in Example 1, the above coating liquid for ink receiving layer was applied by a bar coater and dried,
An inkjet recording material having an ink receiving layer having a dry deposition amount of 1.0 g / m ² was prepared.

The results of evaluation of this ink jet recording material in the same manner as in Example 1 are shown in Table 1.

(Comparative Example 1) The support used in Example 1 was changed to a transparent polyester film having a thickness of 25 μm (Lumirror Q-81: manufactured by Toray Industries, Inc.), and otherwise the example 1
An ink jet recording material was prepared in the same manner as.

The results of evaluation of this ink jet recording material in the same manner as in Example 1 are shown in Table 1.

Comparative Example 2 An ink jet recording material was prepared in the same manner as in Example 1 except that the metal salts of calcium chloride [CaCl ₂ ] and zinc chloride [ZnCl ₂ ] used in Example 1 were not mixed.

The results of evaluation of this ink jet recording material in the same manner as in Example 1 are shown in Table 1.

Comparative Example 3 The support used in Example 1 was changed to Japanese paper having a thickness of 25 μm, and other than that, Example 1 was used.
An ink jet recording material was prepared in the same manner as.

The results of evaluation of this ink jet recording material in the same manner as in Example 1 are shown in Table 1.

[0046]

[Table 1]

[Bledding] Fine lines were printed, and the thin lines were visually evaluated. Those without bleeding were marked with "O", and those with bleeding were marked with "X".

[Curl] Solid printing was carried out on the entire surface, and after drying, the presence or absence of curl was visually evaluated. When no curl was produced, "O" was given, and when curl was produced, "X" was given.

[Drying property] Solid printing was performed on the entire surface, and after a certain period of time had passed after printing, the printed portion was rubbed with a finger, and the ink was not rubbed. did.

[Blocking] Recording material at 20 ° C./65
After leaving it in the atmosphere of% Rh for 24 hours,
The sheets were overlapped and subjected to a constant load, and after a lapse of a predetermined time, they were peeled off and the presence or absence of blocking was evaluated. Those in which blocking did not occur were marked with “◯”, those in which blocking occurred a little were marked with “Δ”, and those with severe blocking were marked with “x”.

The recording materials of Examples 1 and 2 were excellent in all evaluations of bleeding, curling, drying property and blocking. In the recording material of Example 3, since polyvinylpyrrolidone was used for the ink receiving layer, curling during the coating operation was extremely small, and the coating operation could be performed well.

Since the recording material of Comparative Example 1 did not have a paper layer on the support, the drying property and blocking prevention were inferior to those of the examples. The recording material of Comparative Example 2 did not use a metal complex, and thus was inferior in all items as compared with the Example. Since the recording material of Comparative Example 2 used a single Japanese paper for the support, the printed portion was swollen and curled.

[0053]

Since the ink jet recording material of the present invention uses a specific ink receiving layer, the recorded image is excellent in sharpness, curling hardly occurs, and can be suitably used for full color recording.

Further, by using a plastic film obtained by pasting paper on a support and providing a specific ink receiving layer on the paper layer, excellent ink absorbability is obtained, and
Blocking can be greatly reduced.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Matsuyama 4-63 Suzuya, Yono City, Saitama Prefecture Kimoto Central Research Institute

Claims (6)

[Claims] 1. An ink jet recording material having an ink receiving layer containing a complex of a water-soluble resin and a metal salt on at least one side of a support, wherein the support is a plastic film on which paper is laminated on at least one side. An ink jet recording material, wherein the ink receiving layer is laminated on the paper of the support. 2. The ink jet recording material according to claim 1, wherein the water-soluble resin is polyvinyl alcohol. 3. The ink jet recording material according to claim 2, wherein the metal salt is blended in an amount of 0.1 to 30 mol% with respect to the hydroxyl group of polyvinyl alcohol. 4. The ink jet recording material according to claim 1, wherein the water-soluble resin is polyvinylpyrrolidone. 5. The metal salt is 1 with respect to polyvinylpyrrolidone.
5. The composition is blended in an amount of 0 to 200% by weight.
The inkjet recording material described. 6. The ink jet recording material according to claim 1, wherein the metal salt is calcium chloride.