JP2002219859A - Ink jet recording material and image recording body using the material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording material, which shows an excellent luster and a high image density seen from a base material surface side even under the condition that printing is executed by an ink jet system with either a water- based dye ink or a water-based pigment ink and, in addition, is excellent in water resistance and light resistance. SOLUTION: This ink jet recording material is produced by laminating a non-porous ink retaining layer including 50 mass % or more of a hydrophobic resin and an ink penetrating layer including an inorganic pigment, an organic pigment and a binder in the order named on a transparent base material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet system, in which an image is printed, and when the image is observed from the substrate side, excellent gloss, high image density, and good water resistance and light resistance are exhibited. And a recording medium on which an image is printed by an ink jet method using the recording material.

[0002]

2. Description of the Related Art In recent years, ink-jet printing has attracted attention as a recording method capable of high-speed printing and multicolor printing with little noise. This ink-jet recording method uses, for example, electrostatic attraction, mechanical vibration or displacement of the ink using a piezoelectric element, or heating and foaming of the ink, and utilizing the pressure generated at that time. Is produced by spraying a droplet onto a recording material and attaching it to the surface of the recording material.

[0003] As ink for ink jet recording, a pigment ink mainly composed of water, a water-resistant dye ink, and the like are mainly used. When an image is formed on a decorative recording medium, it shows a good color development state but lacks light fastness. In this case, an aqueous pigment ink having good light fastness is mainly used in this case. Therefore, as an ink jet recording material, a material having physical properties suitable for a water-based pigment ink is naturally demanded.

[0004] By the way, the required characteristics of the ink jet recording material are that the ink is promptly received, the shape of the ink dot formed by the attachment of the ink droplet is close to a perfect circle, and feathering occurs. No bleeding at the time of overlapping, high optical density of ink dots, etc.
To achieve high-resolution recording quality comparable to color photos,
Further, it is required that the coloring components of the ink have good color developability, good ink fixability, high surface gloss, and high whiteness.

As an ink jet recording material satisfying such required characteristics, a non-porous ink holding layer mainly composed of a water-soluble or hydrophilic polymer capable of forming a film on a light-transmitting substrate has been used. It has a structure in which an opaque porous ink transport layer is sequentially laminated, and when printing from the ink transport layer side with an aqueous ink by an inkjet method,
Japanese Patent Application Publication No. 5-73586 discloses a device capable of making the ratio A / B of the image density A measured from the substrate side to the image density B measured from the ink transport layer side 1.2 or more. .

[0006] However, in such a recording material, since the ink holding layer is mainly composed of a water-soluble or hydrophilic polymer, cracks occur when the ink-permeable layer is formed, and an image with good visibility cannot be obtained. On the other hand, when the water-based pigment ink is used, there is a drawback that a recorded image is blurred.

[0007]

SUMMARY OF THE INVENTION The present invention provides excellent gloss and high image density when observed from the substrate side, regardless of whether the printing is carried out using an aqueous dye ink or an aqueous pigment ink by an ink jet method. The object of the present invention is to provide a recording material having excellent water resistance and light resistance.

[0008]

Means for Solving the Problems The present inventors have developed an ink jet recording material, particularly an ink jet recording material for forming a multicolor print recording material for indoor or outdoor signboards or decoration or illumination. As a result of various studies, the ink holding layer to be laminated on the base material is formed of a resin containing 50% by mass or more of a hydrophobic resin, and contains an inorganic pigment and an organic pigment as a filler, and ink containing a binder. By using a layer, water resistance, light resistance is excellent,
In addition, they have found that an ink jet recording material that provides a multicolor backprint recording material having high gloss and high image density can be obtained, and based on this finding, have accomplished the present invention.

That is, according to the present invention, a nonporous ink holding layer containing 50% by mass or more of a hydrophobic resin and an ink permeable layer containing an inorganic pigment, an organic pigment and a binder are sequentially laminated on a transparent substrate. A recording material for ink-jet recording, a non-porous ink holding layer containing 50% by mass or more of a hydrophobic resin, and an ink permeable layer containing an inorganic pigment, an organic pigment, and a binder are sequentially laminated on a transparent substrate. In the recording material, an image recording body characterized in that a pigment in an aqueous pigment ink applied for image formation by an inkjet method from the ink transmission layer side is mainly retained at an interface between the ink transmission layer and the ink retaining layer. Is provided.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The transparent base material used in the recording material of the present invention is not particularly limited, and may be arbitrarily selected from synthetic resin films conventionally used as base materials in ink jet recording materials. Can be. Examples of such synthetic resin films include polyethylene terephthalate, polyester resins such as polyethylene naphthalate, polyolefins, olefin resins such as polypropylene, diacetate resins, triacetate resins, polystyrene resins, acrylic resins, and polycarbonate resins. Resin, polyvinyl chloride-based resin, polyvinylidene chloride-based resin, nylon-based resin, polyamide-based resin, polyimide-based resin, and other synthetic resin films. It is preferable to use a synthetic resin film having high transparency, such as cellulose diacetate, polyethylene, and polypropylene. In addition, these synthetic resin films
In order to improve the adhesion to the ink holding layer, a material which has been subjected to an easy adhesion treatment can be used.

Next, the ink-retaining layer of the recording material of the present invention contains a hydrophobic resin in order to make the ink-permeable layer less likely to crack and to improve the ink absorption and the fixability of the aqueous pigment ink. It is necessary to let Here, the hydrophobic resin is a resin that is neither water-soluble nor hydrophilic, and examples of such a resin include polyvinyl acetate-based resins, polyvinyl butyral-based resins, acrylate-based resins, and ethylene-based resins. Vinyl acetate resin, styrene-acrylate resin, polyolefin resin, polystyrene resin, ionomer resin, polyvinyl ether resin, polyester resin, polyamide resin, polyurethane resin, butadiene rubber, acrylonitrile butadiene rubber, etc. Among them, those having hydrophobicity may be mentioned, and particularly preferred are water-insoluble acrylic resins.

These hydrophobic resins are contained in the ink holding layer in an amount of 50% by mass or more, preferably 6% by mass, based on the total mass thereof.
It must be contained in a proportion of 0 to 90% by mass.
If the amount is less than 50% by mass, the ink-permeable layer cannot be formed in close contact with the ink holding layer, so that a crack occurs on the image recording surface. If the amount is more than 90% by mass, the ink absorbing power tends to decrease, and ink bleeding may occur during image formation.

In the ink holding layer, a water-soluble resin or a hydrophilic resin such as polyvinyl alcohol, polyvinyl acetal, hydroxymethylcellulose, carboxymethylcellulose, hydroxyethylcellulose, polyamide, not more than 50% by mass together with the hydrophobic resin. Polyacrylic acid, polymethacrylic acid, sodium polyacrylate, polyvinyl acetate, water-soluble polyester,
It contains natural polymers such as polyethylene oxide and starch, casein, gelatin, polysaccharides and the like. These may be used alone or in combination of two or more.

In the ink holding layer, if desired, a catalyst or a crosslinking agent for the water-soluble resin, for example, a urea resin,
Melamine resins, dimethylol glyoxal monourein, ammonium zirconium carbonate, glycerol polyglycidyl ether, glyoxal, and the like can also be contained. The ink holding layer in the recording material of the present invention is formed on a non-porous layer and has a thickness of 1 to 30 μm.
The range of m is preferred.

Next, in the recording material of the present invention, the ink permeable layer laminated on the ink holding layer needs to contain an inorganic pigment and an organic pigment as a filler. Inorganic pigments play a role in absorbing the solvent of the aqueous ink, capturing the pigment in the ink, and retaining the aqueous ink in the ink permeable layer, such as natural silica, synthetic silica, calcium carbonate, and talc. Used.
Of these, natural silica and synthetic silica are particularly preferred. As the inorganic pigment, an average particle size of 0.1 to 20 μm
m, preferably 1 to 6 μm, particularly preferably 2 to 3 μm
Powder is used.

On the other hand, the organic pigment facilitates the transmission of the ink from the ink permeable layer to the ink holding layer, and particularly transmits the water-based pigment ink, and causes the pigment in the transmitted ink to reach the interface between the transmission layer and the holding layer. It plays a role of retaining the particles, and for example, powders of polymethyl methacrylate, benzoguanamine, polyacrylonitrile and the like are used. The average particle size of this powder is 0.1 to 20 μm, preferably 1 to 6 μm.
μm, particularly preferably in the range of 2-3 μm. The content ratio of the inorganic pigment and the organic pigment in the ink permeable layer is selected within a range of 2: 8 to 8: 2, preferably 3: 7 to 7: 3 by mass ratio. At this time, if the proportion of the inorganic pigment is higher than this, the amount of ink absorbed by the ink-permeable layer and the amount of the captured pigment in the water-based pigment ink are increased, and the amount of ink transmitted to the ink-retaining layer is reduced. The image density when viewed from above becomes low. On the other hand, if the proportion of the inorganic pigment is lower than this, the amount of absorbed ink in the amount of transmitted ink and the amount of the captured pigment in the water-based pigment ink are reduced, resulting in bleeding. As these inorganic and organic pigments, those which are colorless and transparent, colored and transparent, and colored and opaque are used, and those which are colorless and transparent, white and transparent, and white and opaque are particularly preferred.

The compounding amount of the inorganic pigment and the organic pigment in the ink-permeable layer is such that the total amount of the inorganic pigment and the organic pigment is
It is selected so as to fall within a range of 45 to 85% by mass, preferably 60 to 80% by mass with respect to the mass of the ink permeable layer.
If the amount is less than 45% by mass, the ink absorbing ability of the ink-permeable layer will be low, causing bleeding in the recorded image, lowering the whiteness of the recorded material, and deteriorating the visibility of the image. On the other hand, when the content is more than 85% by mass, the ink absorbing ability of the ink transmitting layer increases, and the ink is absorbed in the transmitting layer during image recording, does not reach the ink holding layer, and the recorded image is visually recognized from the substrate surface side. In addition to this, peeling of the coating film easily occurs.

The binder contained in the ink-permeable layer of the present invention is not particularly limited, and may be arbitrarily selected from substances commonly used as binders.
Examples of such a substance include an acrylic resin, a polyvinyl acetate resin, a polyvinyl butyral resin, an acrylate resin, an ethylene-vinyl acetate resin,
Styrene-acrylate resin, polyolefin resin, polystyrene resin, ionomer resin, polyvinyl ether resin, polyester resin, polyamide resin, polyurethane resin, butadiene rubber, acrylonitrile butadiene rubber, polyvinyl alcohol, polyvinyl acetal, Hydroxymethylcellulose, carboxymethylcellulose, hydroxyethylcellulose, polyamide, polyacrylic acid, polymethacrylic acid, sodium polyacrylate, polyvinyl acetate, water-soluble polyester, polyethylene oxide, starch,
Casein, gelatin, polysaccharides and the like. These may be used alone or as a mixture of two or more. It is preferable that the ink transmitting layer contains the same hydrophobic resin as the hydrophobic resin contained in the ink holding layer.

The thickness of the ink permeable layer in the recording material of the present invention is in the range of 1 to 100 μm, preferably 5 to 50 μm.

Next, the operation of the recording material of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic cross-sectional view of an image formed by an inkjet method using a water-based pigment ink for the recording material of the present invention. When an image is formed on the recording material of the present invention by an ink-jet method using a water-based pigment ink, the solvent component 4 of the water-based pigment ink sprayed from the ink-permeable layer side includes the ink-permeable layer 1 and the ink holding layer 2. To spread. However, the pigment component 5 of the water-based pigment ink mainly stays at the interface between the ink transmitting layer 1 and the ink holding layer 2, and forms an image here. Therefore, when viewed from the side of the substrate 3, a very clear, glossy and stable image can be obtained. In this case, the ratio A between the image density A measured from the substrate side and the image density B measured from the ink transmission layer side
The composition and thickness of each layer may be adjusted so that / B is 0.9 or more, preferably 1.2 or more. Since the recording medium thus obtained has water resistance and light resistance, it is suitable for long-term use as a signboard or an illuminated board exposed outdoors.

[0021]

The ink-jet recording material of the present invention comprises:
Since it has high gloss and contains a hydrophobic resin in the ink holding layer, an image having a high image density without cracks on the recording surface is formed. Also, when observed from the substrate side, it provides a clear recorded image having excellent water resistance and light resistance.

[0022]

Next, the present invention will be described in more detail with reference to examples.

The physical properties of the ink jet recording material in each example were evaluated as follows. (1) Cracking property The presence or absence of cracks in the inkjet recording material was visually observed and evaluated according to the following criteria. ：: A clean coating film was formed and no cracks were generated. X: A crack was generated in the coating film. (2) Image density Regarding the recording material for inkjet, an inkjet printer DesignJet manufactured by Hewlett-Packard Company was used.
Solid printing was performed in each of black and magenta colors using a water-based pigment ink at 2500 CP, and the reflection density of the solid printing portion was measured with a reflection densitometer RD-918 manufactured by Macbeth. The measured value from the transparent substrate side was defined as image density A, and the measured value from the ink transmitting layer side was defined as image density B. (3) Image bleeding Inkjet recording material Inkjet printer DesignJet manufactured by Hewlett-Packard Company
An image was output using a water-based pigment ink at 2500 CP, and the bleeding of the output image was visually observed and evaluated according to the following criteria. ：: No bleeding ×: There is bleeding (4) Image visibility Regarding the recording material for inkjet Inkjet printer DesignJet manufactured by Hewlett-Packard
An image was output using an aqueous pigment ink at 2500 CP, and the image visibility was visually observed using reflected light and transmitted light, and evaluated according to the following criteria. ：: good output image ×: bad output image

(5) Transferability of water-based ink The ink jet recording material (Example 2) manufactured by Hewlett-Packard Co., Ltd. as a pigment ink output machine was applied to the ink jet recording material (Example 2) of the present invention.
Using an ink-jet printer PM-750C manufactured by Epson as a dye ink output machine, solid printing is performed in each color of black and magenta, and after drying of the ink, the base material is measured by a reflection densitometer RD-918 manufactured by Macbeth. The reflection density C of the solid printing portion was measured from the surface side. Next, the ink permeable layer of the solid print output was removed, and the reflection density D of the solid print portion was measured from the substrate surface side. The smaller the value of D with respect to C, the lower the migration of the water-based ink.

Example 1 A coating solution A was applied on a 100 μm-thick polyethylene terephthalate film which had been subjected to an easy adhesion treatment by a bar coater method so that the film thickness after drying was 20 μm.
The ink was dried at 130 ° C. for 3 minutes to form an ink holding layer having a thickness of 20 μm. Next, the coating liquid B was dried to a film thickness of 20.
It is applied to the ink holding layer by a bar coater method so as to have a thickness of 20 μm, and dried at 130 ° C. for 2 minutes to have a thickness of 20 μm.
m of the ink-permeable layer was formed to obtain an inkjet recording material. The compositions of the coating liquids A and B are shown below.

Composition of coating liquid A: Acrylic ester copolymer (hydrophobic resin, water-insoluble, 45% aqueous emulsion) 30 parts by mass Polyvinyl alcohol (polymerization degree 1700, saponification degree 80 mol%) 1.5 parts by mass Polyvinylpyrrolidone (average molecular weight 630000) 1.5 parts by weight Urea resin 0.1 parts by weight Ammonium chloride 0.01 parts by weight Water 100 parts by weight Coating liquid B composition: polyvinyl alcohol (polymerization degree 1700, saponification degree 80 mol%) 1 3.0 parts by mass Polyvinyl alcohol (degree of polymerization: 300, degree of saponification: 88 mol%) 3.0 parts by mass Acrylic ester copolymer (hydrophobic resin, water-insoluble, 45% aqueous emulsion) 4.0 parts by mass Crosslinked polymethacrylic methyl resin powder (organic pigment, white, an average particle diameter of 2 [mu] m, the simple BET method surface area of 4m ² / g) 8.0 parts by synthesized Ca powder properties of (inorganic pigments, white, an average particle diameter of 4 [mu] m, the simple BET method surface area of 300 m ² / g) 5.5 parts of ethyl alcohol 40 parts by weight of water 60 parts by inkjet recording materials thus obtained It is shown in Table 2.

Example 2 An ink jet recording material was obtained in the same manner as in Example 1. The compositions of the coating liquids A and B are shown below. Composition of coating liquid A: acrylic ester copolymer (hydrophobic resin, water-insoluble, 45% aqueous emulsion) 20 parts by mass polyvinyl alcohol (polymerization degree 1700, saponification degree 80 mol%) 3 parts by mass polyvinylpyrrolidone (average) (Molecular weight 630000) 3 parts by mass Urea resin 0.1 part by mass Ammonium chloride 0.01 part by mass Water 100 parts by mass Composition of coating solution B: The same as the composition of coating solution B of Example 1. The transferability of the aqueous ink of the ink-jet recording material obtained in this manner is shown in Table 1. The printout of the ink-jet recording material printed by the pigment ink output machine was obtained by adding the aqueous pigment to the interface between the ink-permeable layer and the ink-retaining layer. In the state where the pigment in the ink was retained and the one printed by the dye ink output machine, the ink was not retained at the interface between the ink transmitting layer and the ink holding layer. Table 2 shows other physical properties of the inkjet recording material.

[0028]

[Table 1]

Comparative Example 1 10 parts by mass of cation-modified polyvinyl alcohol (water-soluble resin, polymerization degree 1800, saponification degree 85 mol%) and water 90 parts by mass on a 100 μm-thick polyethylene terephthalate film which was previously subjected to an easy adhesion treatment. Was applied by a bar coater method so that the film thickness after drying was 3 μm, and dried at 100 ° C. for 10 minutes to form an ink holding layer having a thickness of 3 μm. Next, a coating liquid having the following composition is applied on the ink holding layer by a bar coater method so that the film thickness after drying is 20 μm, and dried at 80 ° C. for 2 minutes to form a 20 μm thick ink transmitting layer. Was formed to obtain a recording material for inkjet. Coating liquid composition: Polyvinyl alcohol (degree of polymerization 1700, degree of saponification 98.5 mol%) 10 parts by mass Polymethacrylate resin (organic pigment, average particle size 8 to 10 μm) 100 parts by mass Polyoxyethylene derivative (surfactant) 0 0.05 mass parts water 290 mass parts The physical properties of the ink jet recording material thus obtained are shown in Table 2.

Comparative Example 2 An ink jet recording material was obtained in the same manner as in Example 1. The compositions of the coating liquids A and B are shown below. Composition of coating liquid A: acrylic ester copolymer (hydrophobic resin, water-insoluble, 45% aqueous emulsion) 20 parts by mass polyvinyl alcohol (polymerization degree 1700, saponification degree 80 mol%) 3 parts by mass polyvinylpyrrolidone (average) (Molecular weight 630000) 3 parts by weight Urea resin 0.1 part by weight Ammonium chloride 0.01 part by weight Water 100 parts by weight Composition of coating liquid B: Polyvinyl alcohol (polymerization degree 1700, saponification degree 80 mol%) 1.0 part by weight Polyvinyl Alcohol (degree of polymerization: 300, degree of saponification: 88 mol%) 3.0 parts by mass Acrylate copolymer (hydrophobic resin, water-insoluble, 45% aqueous emulsion) 4.0 parts by mass Crosslinked poly (methyl methacrylate) resin powder ( organic pigments, white, an average particle diameter of 2 [mu] m, the simple BET method surface area of 4m ² / g) 13.5 parts by mass of ethyl alcohol 40 Properties of the amount of water 60 parts by inkjet recording materials thus obtained are shown in Table 2.

Comparative Example 3 An ink jet recording material was obtained in the same manner as in Example 1. The compositions of the coating liquids A and B are shown below. Composition of coating liquid A: acrylic ester copolymer (hydrophobic resin, water-insoluble, 45% aqueous emulsion) 20 parts by mass polyvinyl alcohol (polymerization degree 1700, saponification degree 80 mol%) 3 parts by mass polyvinylpyrrolidone (average) (Molecular weight 630000) 3 parts by weight Urea resin 0.1 part by weight Ammonium chloride 0.01 part by weight Water 100 parts by weight Composition of coating liquid B: Polyvinyl alcohol (polymerization degree 1700, saponification degree 80 mol%) 1.0 part by weight Polyvinyl Alcohol (degree of polymerization 300, saponification degree 88 mol%) 3.0 parts by mass Acrylic ester copolymer (hydrophobic resin, water-insoluble, 45% aqueous emulsion) 4.0 parts by mass Synthetic silica powder (inorganic pigment, white) , an average particle diameter of 4 [mu] m, the simple BET method surface area of 300 m ² / g) 13.5 parts by mass of ethyl alcohol 40 parts by mass of water 60 quality Part shows the physical properties of ink-jet recording material thus obtained in Table 2.

Comparative Example 4 An ink jet recording material was obtained in the same manner as in Example 1. The compositions of the coating liquids A and B are shown below. Composition of Coating Liquid A: Acrylic ester copolymer (hydrophobic resin, water-insoluble, 45% aqueous emulsion) 26 parts by mass Urea resin 0.1 parts by mass Ammonium chloride 0.01 parts by mass Water 100 parts by mass Composition of liquid B: the same as the composition of coating liquid B in Example 1. Table 2 shows the physical properties of the ink jet recording material thus obtained.

[0033]

[Table 2]

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of an image formed by an inkjet method using a water-based pigment ink for a recording material of the present invention.

[Description of Signs] 1 Ink permeable layer 2 Ink holding layer 3 Transparent substrate 4 Solvent component of aqueous pigment ink 5 Pigment component of aqueous pigment ink

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] February 5, 2001 (2001.2.5)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0033

[Correction method] Change

[Correction contents]

[0033]

[Table 2]

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shoji Nishimoto 4-11-2 Ginza, Chuo-ku, Tokyo F-term (reference) 2C056 EA04 EA13 FB02 FC06 2H086 BA13 BA15 BA33 BA36 BA41

Claims (5)

[Claims] 1. An ink jet recording material comprising a transparent substrate and a non-porous ink holding layer containing 50% by mass or more of a hydrophobic resin and an ink permeable layer containing a filler and a binder sequentially laminated on the transparent substrate. 2. The ink-jet recording material according to claim 1, wherein the hydrophobic resin is a water-insoluble acrylic resin. 3. The ink-permeable layer contains, as a filler, an inorganic pigment and an organic pigment in a mass ratio of 2: 8 to 8: 2, and the total amount of these pigments is the total mass of the ink-permeable layer. 2. The amount is in the range of 45 to 85% by mass based on
Or the recording material for inkjet according to 2. 4. In an image recorded by an ink-jet method, the ratio A / B of the image density A measured from the transparent substrate surface side to the image density B measured from the ink transmission layer side is 0.
4. The ink jet recording material according to claim 1, wherein the number is 9 or more. 5. A recording material in which a non-porous ink holding layer containing 50% by mass or more of a hydrophobic resin and an ink permeable layer containing a filler and a binder are successively laminated on a transparent base material, An image recording material, wherein a pigment in an aqueous pigment ink applied for image formation by an ink jet method from a layer side mainly stays at an interface between an ink transmitting layer and an ink holding layer.