JPH0911613A - Recording medium and ink jet recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To record an image excellent in preservability. SOLUTION: An ink compsn. contains at least one dye selected from a group consisting of a styrbene azo dye, a triphenylmethane dye and a xanthene dye as a coloring agent. As a recording medium, an ink jet recording medium having a recording layer consisting of at least silica and a binder provided thereto is used. 5-55wt.% of one of polymeric components of the binder is styrene/ butadiene latex and 20-45wt.% of the styrene/butadiene latex is a component derived from a butadiene monomer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium and a recording method capable of realizing an image excellent in storability, and more particularly to an inkjet recording method capable of realizing an image excellent in storability and a recording medium used therein.

2. Description of the Related Art The ink jet recording method is a method in which small droplets of ink are ejected by various mechanisms and deposited on the recording medium to form ink dots. It has the advantages of low noise, high-speed printing, and easy full-color printing.

Also in the ink jet recording method, the storage stability of the printed matter is an important characteristic. Dyes, which are organic substances, are generally used as coloring materials for ink compositions used in inkjet recording methods. Therefore, the dye may be decomposed and the color tone may be changed by contact with ultraviolet rays or highly active gas. In addition, as a recording medium used in the ink jet recording method, a recording medium on which silica is supported may be used. This silica has a large specific surface area, has catalytic activity, and may catalyze the oxidation of dyes.

Up to now, there have been proposed some methods for improving the storability of images. For example, JP-A-57-87
No. 989 discloses a recording layer containing a metal oxide, a metal chloride,
It is disclosed that the light resistance is improved by adding tannic acid or the like. Further, a technique has been proposed in which various substances considered to function as an antioxidant are added to the recording layer. For example, JP-A-61-61887 discloses a polyallylamine derivative and JP-A-61-14659 discloses.
No. 1 discloses a hindered amine compound, which is disclosed in
Japanese Patent Laid-Open No. 154989 discloses a technique of adding a hydrazide compound to a recording medium, and Japanese Patent Application Laid-Open No. 61-163886 discloses a technique of adding a thiourea derivative, a thiosemicarbazide derivative and a thiocarbohydrazide derivative to a recording medium.

On the other hand, some dyes have poor storability. In particular, there are known dyes whose discoloration with time is observed even in the environment where they are not directly exposed to light, and such dyes are those that are decomposed by an oxidizing gas present in the air, for example, ozone. I think that the.

[0006]

SUMMARY OF THE INVENTION The present inventors have now surprisingly found that the combination of a recording medium having a specific composition with a dye, which is generally inferior in the preservability, improves the preservability of images. . The present invention is based on this finding. Therefore, the present invention is a recording medium excellent in image storability,
In particular, the purpose is to provide a recording medium for inkjet recording. Another object of the present invention is to provide a recording method having excellent image storability, especially an inkjet recording method.

The recording medium according to the present invention is a recording medium for ink-jet recording provided with a recording layer comprising at least silica and a binder, and contains 5 to 55 parts by weight of the polymer component of the binder. % Is styrene-butadiene latex, and 20 to 45% by weight of the styrene-butadiene latex is derived from butadiene monomer. The recording method according to the present invention records on the recording medium with an ink composition containing at least one dye selected from the group consisting of stilbene azo dyes, triphenylmethane dyes, and xanthene dyes as a colorant. Is what you do.

Furthermore, the ink jet recording method according to the present invention is an ink jet recording method comprising a step of ejecting droplets of an ink composition to form ink dots on a recording medium, wherein the ink composition is a colorant. As a stilbene azo dye, a triphenylmethane dye, and at least one dye selected from the group consisting of xanthene dyes, the recording medium using the recording medium according to the present invention, Is.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The recording medium according to the present invention is provided with a recording layer comprising at least silica and a binder, preferably on the surface thereof. In the present invention, 5 to 55% by weight of the polymer component of the binder is styrene-butadiene latex, and 20 to 45% by weight of the styrene-butadiene latex is derived from butadiene monomer. Here, these weight% are primarily the amounts charged as the binder composition described in the production method described later, but the weight% is the dry amount when the final recording medium is used. It corresponds to the weight% of each component in the polymer component of the binder in the recording layer.

In the present invention, a part of the binder in the recording layer is the above-mentioned specific styrene-butadiene latex, so that the image storability is improved. In particular, in combination with the specific dye described below, a very good improvement in image storability is observed. Without intending to be bound by the theory below, it is believed that such improvement in image storability is due to the interaction of the dye in the ink composition and the binder in the recording layer. Particularly, when the butadiene component is abundant, it is considered that two or more same components are adjacent to each other and have a plurality of aliphatic double bonds having relatively high reactivity even after the polymerization.

A water-soluble polymer is preferably added as a component other than the styrene-butadiene latex as a binder. Specific preferred examples thereof include starches such as oxidized starch and esterified starch; carboxymethyl cellulose,
Cellulose derivatives such as hydroxyethyl cellulose; polyvinyl alcohol and its derivatives; polyvinylpyrrolidone; casein; gelatin and the like.
Polyvinyl alcohol is particularly preferable.

Further, the binder may be added with components commonly used as other binders, and specific examples thereof include water-based resins such as acrylic emulsion, styrene-acrylic emulsion and vinyl acetate emulsion. To be Silica as a pigment is added to the recording layer of the recording medium according to the present invention. As this silica, synthetic silica is preferably used, and examples thereof include synthetic silica such as amorphous silica and amorphous silica. In addition, Chemical Handbook Applied Chemistry (October 15, 1986 published by Maruzen Co., Ltd.
The silica gel, white carbon and anhydrous silica described on page 256 of the Chemical Society of Japan can be preferably used,
White carbon is particularly preferable.

The abundance ratio of the binder and silica may be appropriately determined, but it is preferable that the binder: silica ratio in the recording layer is about 0.1 to 1: 1 by weight, more preferably. Is about 0.2 to 0.8: 1.

The recording medium according to the present invention is produced by preparing a coating liquid containing the above silica and the above binder and applying the coating liquid to a recording medium substrate such as paper. You can The coating liquid can be prepared by stirring and mixing the silica, the binder, and water. The blending amount of silica and the binder may be determined in consideration of the composition ratio in the recording layer obtained in the above-mentioned final body, but the silica is sufficiently bound to the base material and ink is absorbed. It is preferable to consider the composition so that the porous structure of (1) is not destroyed. Further, this coating liquid contains a pigment dispersant, a water retention agent, a thickener, an antifoaming agent, a preservative, a colorant, a water-proofing agent, a wetting agent, a fluorescent dye, an ultraviolet absorber, a cationic agent, if necessary. A polymer electrolyte or the like can be added as appropriate.

The coating amount on the recording medium substrate may be appropriately determined within the range where a recording layer capable of improving image storability is formed, but is preferably 10 to 25 g / m ² in terms of solid content. , And more preferably 13 to 22 g / m ² . As a coating method, a blade coater, an air knife coater,
A coating method using a known coating machine such as a roll coater, a kiss coater, a squeeze coater, a curtain coater, a bar coater, a gravure coater, and a comma coater can be appropriately selected and used.

According to a preferred embodiment of the present invention, the recording medium contains at least one dye selected from the group consisting of stilbenazo dyes, triphenylmethane dyes, and xanthene dyes as a colorant. The storability of an image recorded using the ink composition is greatly improved.

Specific examples of these dyes include dyes represented by the following formula (I), (II), (III) or (IV).

[0018]

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(In the above formula, X represents a cation species, and R ¹
And R ² , and R ³ and R ⁴ are independently a hydrogen atom, a hydroxyl group, a lower alkyl group, a lower alkoxy group,
A group —COOX (where X represents the same meaning as described above) or a group —SO ₃ X (wherein X represents the same meaning as described above), and R ⁵ , R ⁶ , R ⁷ , And R ⁸ ,
And R ⁹ , R ¹⁰ , R ¹¹ , and R ¹² independently represent a hydrogen atom, a hydroxyl group, an amino group, or a group —SO ₃ X (where X has the same meaning as above), and R ¹³ ,
R ¹⁴ , R ¹⁵ , and R ¹⁶ independently represent a hydrogen atom, a lower alkyl group, or an optionally substituted phenyl lower alkyl group, and R ¹⁷ , R ¹⁸ , and R ¹⁹ independently represent , A hydrogen atom or a lower alkyl group, R ²⁰ and R ²¹ independently represent a hydrogen atom, a lower alkyl group, or a phenyl lower alkyl group, R ²² represents a hydrogen atom or a lower alkyl group, and R ²³ , R ²⁴ , and R
²⁵ is a hydrogen atom, a halogen atom, or a group -COOX
(Where X represents the same meaning as described above), or a group-
SO ₃ X (where X represents the same meaning as described above). )

The lower alkyl group as a group or part of a group in the above formula represents a linear or branched C ₁ ~ ₆ alkyl group, preferably means C ₁ ~ ₄ alkyl group.

The cation species represented by X in the formula preferably means an alkali metal or an alkaline earth metal.
In addition, the halogen atom represents any one of fluorine, chlorine, bromine and iodine. One or more hydrogen atoms on the phenyl group of the phenyl lower alkyl group represented by R ¹³ , R ¹⁴ , R ¹⁵ , and R ¹⁶ may be substituted, and the substituent includes a group —SO ₃ X (here And X represents the same meaning as described above), or a group —SO ₃ NH4X (wherein X represents the same meaning as described above).

Preferred specific examples of the dyes represented by these general formulas are (A-1) to (A-6) and (B) below.
-1) to (B-4) and (C-1) to (C-5) dyes.

[0023]

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[0024]

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[0025]

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[0026]

[Chemical 6]

The ink composition used in the present invention may be an ink composition suitable for the recording method except that it contains the above dye as a colorant. For example, it may be a usual ink composition used for inkjet recording.

The ink composition used particularly for ink jet recording may basically consist of an organic solvent and water in addition to the colorant. As a preferable example of the organic solvent,
Glycerin, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol,
High boiling and low volatility polyhydric alcohols such as dipropylene glycol, hexylene glycol, polyethylene glycol and polypropylene glycol are used.
Methyl 2-pyrrolidone, 1,3-dimethylimidazolidinone, monoethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, diethanolamine, Nn-butyldiethanolamine,
A water-soluble organic solvent such as a nitrogen-containing organic solvent such as triisopropanolamine or triethanolamine can be added within a range in which printing bleeding does not occur. Particularly, diethylene glycol, glycerin and the like are preferable. Further, addition of benzotriazole is preferable from the viewpoint of stabilizing the physical properties of the ink composition.

[0029]

The present invention will be described in more detail with reference to examples, but the present invention is not limited thereto. Production Example Production of Styrene-Butadiene Latex 100 parts by weight of ion-exchanged water, 2 parts by weight of sodium dodecylbenzenesulfonate, in a pressure resistant polymerization reaction vessel,
0.1 parts by weight of dodecyl mercaptan and 0.5 parts by weight of ammonium persulfate were charged and sufficiently stirred. Then, each monomer shown in Table 1 below was added, and polymerization was started at 65 ° C. The polymerization was terminated when the conversion of polymerization reached 98%. Next, these copolymer latexes were adjusted to pH 7 with an aqueous ammonia solution to obtain styrene-butadiene latex (SBR) A to E shown in Table 1 below.

[0030]

[Table 1]

Example A1 85 parts by weight of LBKP (csf 300 ml), 15 parts by weight of light calcium carbonate, 0.02 part by weight of internally added size (alkyl ketene dimer system), 1.0 part by weight of sulfuric acid band, and 0.5 part by weight of cationized starch was blended and a base paper having a basis weight of 80 g / m ² was made with a Fourdrinier paper machine. next,
100 parts by weight of synthetic silica (Fineseal X-37: manufactured by Tokuyama Corporation) was dispersed in 340 parts by weight of water. To the obtained dispersion, styrene prepared above as a binder was added.
A solution prepared by dissolving 10 parts by weight of butadiene latex A and 40 parts by weight of polyvinyl alcohol (PVA105: manufactured by Kuraray Co., Ltd.) in 350 parts by weight of water and further adding a bluish dye and a fluorescent dye to obtain a coating liquid. . The obtained coating liquid was applied to the base paper by roll coating and then dried to obtain an inkjet recording paper. The coated amount of the obtained paper was 14 g / m ² .

Example A2 20 parts by weight of styrene-butadiene latex B, 30 parts by weight of polyvinyl alcohol, and coating amount of 17 g / m ²
An inkjet recording paper was obtained in the same manner as in Example 1 except that the above was used. Example A3 An inkjet recording paper was obtained in the same manner as in Example 1 except that styrene-butadiene latex C was used. Example A4 15 parts by weight of styrene-butadiene latex D, 35 parts by weight of polyvinyl alcohol, and coating amount of 21 g / m ²
An inkjet recording paper was obtained in the same manner as in Example 3 except that the above was adopted.

Comparative Example A1 An ink jet recording paper was obtained in exactly the same manner as in Example 1 except that the styrene / butadiene latex was not added and the coating amount was 17 g / m ² . Comparative Example A2 An inkjet recording paper was obtained in the same manner as in Example 1 except that styrene-butadiene latex E was used and the coating amount was 21 g / m ² . Comparative Example A3 30 parts by weight of styrene-butadiene latex C, 20 parts by weight of polyvinyl alcohol, and coating amount of 17 g / m ²
An inkjet recording paper was obtained in the same manner as in Example 3 except that the above was adopted. Comparative Example A4 Tannic acid was added to the coating solution of Comparative Example 1 as an antioxidant in an amount of 0.
An inkjet recording paper was obtained in the same manner as in Comparative Example 1 except that 5 parts by weight was added.

Example B An ink composition having the composition shown in Table 2 below was prepared.
The dye numbers in the table are the dye numbers described above.

[0035]

[Table 2]

Evaluation Test The storability of the image on the above recording medium was evaluated as follows. Using a Mach jet printer MJ-500 (manufactured by Seiko Epson Corporation), the above Examples B1 to B4
The above ink composition was solid printed (100% duty).

Print Density The print density of the printed matter was measured at 5 points for each color with a Masbeth densitometer RD-514, and the average was obtained. The value was evaluated as follows. Print density exceeds 1.2 ... ○ 1.1 to 1.2 ... △ less than 1.1 ... ×

[0038] The storage stability thereof printed matter, ozone concentration 30ppm in a sealed container placed removed after 5 minutes was, was evaluated in the following criteria. (A) Discoloration of printed part 1. Almost no discoloration is observed. Some discoloration is observed ... △ 3. Significant discoloration ... × (b) Yellowing of white paper 1. Almost no yellowing is observed. Some yellowing is observed ... △ 3. Yellowing is remarkable ... ×

The results are shown in Table 3 below.

[Table 3]

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Junichi Iida 3-5 Yamato 3-chome, Suwa City, Nagano Seiko Epson Corporation (72) Inventor Yukio Kobayashi 1-30 Kamiochiai, Shinjuku-ku, Tokyo 6 Nippon Paper Industries Co., Ltd. Product Development Laboratory (72) Inventor Yoshihiro Kuroyama 1-30-6 Kamiochiai, Shinjuku-ku, Tokyo Japan Paper Manufacturing Co., Ltd. Product Development Laboratory (72) Inventor Hiroki Midorikawa Asahi, Shirakawa City, Fukushima Prefecture 3-chome 3

Claims (9)

[Claims] 1. A recording medium for ink jet recording, comprising a recording layer comprising at least silica and a binder, wherein 5 to 55% by weight of the polymer component of the binder is styrene-butadiene latex. Yes, the styrene
A recording medium in which 20 to 45% by weight of the butadiene latex is derived from a butadiene monomer. 2. The polymer component of the binder other than the styrene-butadiene latex is a water-soluble polymer.
The recording medium described. 3. The recording medium according to claim 2, wherein the water-soluble polymer is polyvinyl alcohol. 4. The recording layer is provided on the surface of the recording layer,
The recording medium according to claim 1. 5. An inkjet recording method using an ink composition containing at least one dye selected from the group consisting of stilbene azo dyes, triphenylmethane dyes, and xanthene dyes as a colorant. The recording medium according to claim 1. 6. A recording medium according to claim 5, wherein the dye as a colorant in the ink composition is represented by the following formula (I), (II), (III) or (IV). . Embedded image (In the above formula, X represents a cationic species, R ¹ and R ² , and R ³ and R ⁴ are independently a hydrogen atom, a hydroxyl group, a lower alkyl group, a lower alkoxy group, a group —COOX (wherein X represents the same meaning as described above) or a group —SO ₃ X (where X represents the same meaning as described above), and R ⁵ , R ⁶ , R ⁷ , and R ⁸ and R ⁹ , R ¹⁰ ,
R ¹¹ and R ¹² independently represent a hydrogen atom, a hydroxyl group, an amino group, or a group —SO ₃ X (where X represents the same meaning as described above), and R ¹³ , R ¹⁴ and R ¹⁵ , And R ¹⁶ independently represent a hydrogen atom, a lower alkyl group, or an optionally substituted phenyl lower alkyl group, and R ¹⁷ , R ¹⁸ , and R ¹⁹ independently represent a hydrogen atom or a lower atom. Represents an alkyl group, R ²⁰ and R ²¹ independently represent a hydrogen atom, a lower alkyl group, or a phenyl lower alkyl group, R ²² represents a hydrogen atom or a lower alkyl group, and R ²³ , R ²⁴ , And R ²⁵ are a hydrogen atom, a halogen atom,
Or a group -COOX (wherein, X represents a meaning of the same as above), or -SO ₃ X (where, X represents a meaning same to the above) based representative of. ) 7. An ink composition comprising at least one dye selected from the group consisting of stilbene azo dyes, triphenylmethane dyes, and xanthene dyes as a colorant, according to any one of claims 1 to 4. A recording method for recording on the recording medium according to 1 above. 8. An ink jet recording method comprising a step of ejecting droplets of an ink composition to form ink dots on a recording medium, wherein the ink composition is a stilbene azo dye, tri dye as a colorant. An ink jet recording, comprising at least one dye selected from the group consisting of a phenylmethane dye and a xanthene dye, wherein the recording medium is the one according to any one of claims 1 to 4. Method. 9. The dye according to claim 7, wherein the dye as a colorant is represented by the formula (I), (II), (III) or (IV) defined in claim 6. Inkjet recording method.