JPH08282091A - Ink jet recording material - Google Patents

Abstract

PURPOSE: To obtain a recording material excellent in water resistance and durability and usable even in the open air by providing an ink fixing coating layer containing at least water-insoluble cellulose on a support selected from a resin film and synthetic paper and further laminating an ink receiving coating layer containing pigment and a resin thereon. CONSTITUTION: An ink jet recording material developing an excellent hue, imparting an excellent dot shape and provided with characteristics such as water resistance or preservability is obtained by providing an ink fixing coating layer composed of paper containing water-insoluble cellulose on a support selected from a resin film and synthetic paper and further laminating an ink receiving coating layer containing pigment and a resin thereon. As water- insoluble cellulose, at least one kind of cellulose selected from cellulose pulp, a cellulose powder and microfibrilated cellulose is used. As the pigment, fine powdery synthetic silica is used. As the support, a resin film composed of a polyolefin resin being a thermoplastic resin is used.

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, and particularly to excellent color development, dot shape, water resistance,
The present invention relates to an inkjet recording material having characteristics such as storability.

[0002]

2. Description of the Related Art The performance of ink jet printers using water-based inks, especially the improvement in printing speed, resolution, saturation, etc., enables high-speed absorption even on recording materials,
Higher characteristics such as high absorption capacity and controlled ink bleeding are required, and coated papers having an ink-receptive coating layer on the surface have been developed.

For example, Japanese Unexamined Patent Publication (Kokai) No. 62-158084 discloses a method for producing an ink jet recording medium having high water-based ink absorbency, color reproducibility and color density by using fine particle synthetic silica. That is, in order to comply with the required characteristics described above, it is carried out to provide a coating layer containing a white pigment having excellent liquid absorbing property such as fine particle synthetic silica as a main component on the surface of a base paper containing cellulose pulp as a main component. ing.

Recently, the ink jet recording material is used not only as an office document indoors but also because it can be easily printed, it tends to be used outdoors for posting, and the durability of the paper, especially the water resistance of the substrate is required. Has been done. When the base material is paper, there is a problem that the base material is torn when wet with rain or the like and cannot be used continuously.

As a means for improving this, for example, Japanese Unexamined Patent Publication No.
Japanese Patent No. 82589 discloses a water-resistant inkjet recording paper in which a sheet composed of a mono-biaxially stretched film having a multilayer structure containing a polyolefin containing an inorganic pigment as a main component is provided with an ink-receptive coating layer. When such a film is printed, since the film is not breathable, even if the ink is dry on the surface, the ink moves inside the coating layer, causing color bleeding over time, and lowering the image quality. It was observed.

In order to solve such a problem, various methods of containing a cationic resin or a resin having a cationic functional group have been taken so far. For example, Japanese Examination 4-
Japanese Patent Publication No. 15746 discloses a method of containing a cationic dicyanamide resin. However, in all cases, the effect was small when the film was used as a support.

Further, for example, Japanese Unexamined Patent Publication (Kokai) No. 4-257483 discloses a recording paper in which fine fiberized pulp and porous pigment are provided on the surface of a paper support by a size press method. However, since the support is paper, the durability and water resistance of the paper are poor and it cannot be used outdoors.

[0008]

DISCLOSURE OF THE INVENTION The present invention is capable of printing high-quality images at high speed using an ink jet printer, is excellent in water resistance and durability, and can be used outdoors. It is an object of the present invention to provide an ink jet recording material which is high in color, has no color bleeding over time after printing, and can suppress deterioration of image quality.

[0009]

The present invention includes the following aspects. [1] An inkjet formed by providing an ink-fixing coating layer containing at least water-insoluble cellulose on a support selected from a resin film and synthetic paper, and further laminating an ink-receiving coating layer containing a pigment and a resin. Recording material.

[2] The ink jet recording material according to [1], wherein the water-insoluble cellulose contained in the ink-fixing coating layer is at least one selected from cellulose pulp, cellulose powder, and microfibrillated cellulose.

[3] The ink jet recording material according to [1], wherein the ink fixing coating layer is paper.

[4] The ink jet recording material according to [1], wherein the pigment contained in the ink receptive coating layer is fine powder synthetic silica.

[0013]

The resin film used as the support in the present invention is
Examples of the thermoplastic resin include polyolefin resins such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, and those containing these as the main components. Other thermoplastic resins such as polystyrene and acrylic acid ester copolymers may be mixed and used.

Films formed by stretching these thermoplastic resins in the machine direction and / or the transverse direction may also be used. In addition, inorganic fine powder may be mixed with this thermoplastic resin to form a film, which may be biaxially stretched to form a paper-like layer. In the present invention, a multilayer film obtained by laminating a plurality of such films can be used as a support. For example, a two- to three-layer film in which a paper-like layer is provided on both sides or one side of the base material layer, or 3-5 in which a surface layer is further formed on at least one side of the paper-like layer.
The use of a layer film or the like is effective. A paper-like layer of a thermoplastic resin is generally known as synthetic paper.

Such a film has a thickness of 15 to 20.
Generally, a thickness of about 0 μm is preferable. The basis weight is 10
˜150 g / m ² is preferable, but not particularly limited.

Since the support used in the present invention has neither absorbability nor breathability, when used as an ink jet recording material, it is necessary to provide a coating layer for absorbing ink on the support. Therefore, the solvent in the ink absorbed in the coating layer at the time of printing, such as water or solvent, cannot escape to the atmosphere from the support side, and is retained in the coating layer as compared with a normal paper support. It takes a long time. As a result, the dye in the ink is not fixed and easily moves, and the ink moves to the surface of the coating layer during storage, causing problems such as color bleeding.

Therefore, in the present invention, an ink fixing coating layer containing a water-insoluble cellulose is provided between the ink receiving coating layer and the resin film or synthetic paper. The ink-fixing coating layer absorbs ink, particularly the solvent component contained in the ink, to prevent the dye in the ink from migrating with the migration of the solvent, and to prevent image bleeding such as color bleeding over time. It was found that the decrease can be suppressed.

The mechanism by which the ink-fixing coating layer of the present invention suppresses the movement of ink is not clear, but the solvent-absorbing ability and solvent of the water-insoluble cellulose contained in the ink-fixing coating layer due to the capillary phenomenon. It is presumed that this is due to the holding power. Further, when the solvent is a polar solvent such as alcohol, it is considered that the solvent is fixed by hydrogen bond with the OH group in the water-insoluble cellulose.

The water-insoluble cellulose is preferably cellulose pulp, or paper obtained by making cellulose pulp into paper, or microfibrillated cellulose in which pulp is made into fine fibers by a physical method to increase the surface area. As the water-insoluble cellulose used in the present invention, red pine, black pine, spruce pine, Todo pine, conifer such as cedar, beech, birch, groundwood such as hardwood such as cypress, etc. as a main raw material, sulphite pulp, kraft pulp, semi. Cellulose pulp such as chemical pulp, chemi-ground pulp, refiner ground pulp, or used paper pulp; dissolving pulp such as viscose; and microfibrillated cellulose obtained by increasing the surface area of the above pulp as fine fibers by a physical method; cellulose. Cellulose powder finely pulverized by acid hydrolysis and mechanical treatment in combination or by mechanical treatment; other than the above pulp as a main component, clay, talc, calcium carbonate, calcined kaolin, aluminum oxide, aluminum hydroxide Inorganic pigments such as titanium oxide and urea resin fine particles Contains pigments, and as additives, internal sizing agents such as rosin, alkyl ketene dimer and alkenyl succinic acid, sulfuric acid bands, fixing agents such as cationic starch, polyacrylamide polymers, paper strengthening agents such as starch, etc. Examples of the paper include papers which are appropriately selected and internally added and paper-made by a known paper machine.

The paper may be made of rosin-based, petroleum resin-based, starch such as oxidized starch, acetylated starch and hydroxyethylated starch and its derivatives, polyvinyl alcohol and its derivatives, styrene, alkyd, polyamide, acryl and olefins, if necessary. The size treatment may be carried out with a synthetic resin system consisting of a polymer such as maleic acid, vinyl acetate or the like or a copolymer of two or more thereof, and a surface sizing agent such as a synthetic resin emulsion system or a wax system thereof. Acid paper,
There is neutral paper.

The microfibrillated cellulose is produced by using a known beating equipment such as a beater, a conical refiner, a cylindrical refiner, a single disc refiner, and a double disc refiner.

In the ink-fixing coating layer of the present invention, in addition to the water-insoluble celluloses, a resin may coexist in order to enhance the adhesive strength. Such resins include polyvinyl alcohol and derivatives modified with silanol groups, polyvinylpyrrolidone, proteins such as casein, starch and its derivatives, styrene-butadiene copolymer,
Conjugated diene-based polymer latex such as methyl methacrylate-butadiene copolymer, acrylic-based polymer latex such as polymer or copolymer of acrylic acid ester and methacrylic acid ester, vinyl-based polymer such as ethylene-vinyl acetate copolymer Combined latex or modified polymer latex containing functional groups such as carboxyl groups and cationic groups of these various polymers, synthetic resin-based water-based adhesives such as thermosetting resins such as melamine resins and urea resins, and maleic anhydride Polymers such as polymer resin, polyacrylamide, polymethylmethacrylate, polyurethane resin, unsaturated polyester resin, polyvinyl butyral, alkyd resin, and other synthetic resin adhesives are used. In addition to this, inorganic pigments, organic pigments and the like may be mixed.

Paper (paper-like layer) as an ink-fixing coating layer
When using, the support and the paper are adhered. Such adhesives include starch and its derivatives, glue, proteins such as casein, polyvinyl alcohol and its derivatives, styrene-butadiene copolymers, conjugated diene polymer latexes such as methyl methacrylate-butadiene copolymers, acrylics. Acrylic polymer latexes such as polymers or copolymers of acid esters and methacrylic acid esters, vinyl polymer latexes such as ethylene-vinyl acetate copolymers, carboxyl groups and cationic groups of these various polymers Functional group-containing modified polymer latex, melamine resin, synthetic resin-based water-based adhesive such as thermosetting resin such as urea resin, maleic anhydride copolymer resin system,
Polyacrylamide type, polymethylmethacrylate type, polyurethane resin type, unsaturated polyester resin type,
Polymer such as polyvinyl butyral-based and alkyd resin-based synthetic resin adhesives, ethylene vinyl alcohol, styrene-butadiene copolymers, isoprene-styrene copolymers and other hot-melt adhesives adhere to the support and paper. Is good and is preferably used.

In addition to these, as additives, pigment dispersants, defoamers, colorants, antioxidants, ultraviolet absorbers, viscosity modifiers,
A cross-linking agent, a cation resin for improving the water resistance of the printed matter after inkjet recording, etc. are appropriately used according to the production conditions, the printing quality and the required performance. When laminating paper on resin film or synthetic paper, the basis weight of the paper is 10-100
It is preferably about g / m ² . The thickness of the paper is 1-100μ
About m is preferable, but it is not particularly limited and can be appropriately selected depending on the application. Also, the degree of paper size is 1
About 20 seconds is preferable. If the time exceeds 20 seconds, the ink absorption capacity decreases, and it becomes difficult to fix the solvent component in the ink. The ash content of the paper is not particularly limited, but it is 1 to 1
8% is preferable.

The ink-receptive coating layer is a layer that contributes to ink absorption, fixation of dye in the ink, and color development of the dye. The pigment used in the ink-receptive coating layer is porous and has a low ink absorptivity. It is preferable to contain a pigment that enables high and clear color development. As such a pigment,
Examples include fine particle synthetic silica, zeolite, calcium carbonate, calcium silicate, aluminum hydroxide, calcined clay, kaolin clay, talc, white carbon, organic pigments (plastic pigments), and pigments commonly used for paper coating. It is particularly preferable to use fine particle synthetic silica.

Although the use ratio of such a pigment is not limited, it is 50 to 90% by weight of the total solid content of the coating layer. 50%
If it is less than 90%, the ink absorbency becomes insufficient, and if it exceeds 90%, the strength of the ink-receptive coating layer may decrease.

The resin used in the ink-receptive coating layer of the present invention includes polyvinyl alcohol and derivatives modified with silanol groups, proteins such as polyvinylpyrrolidone and casein, starch and its derivatives, styrene-butadiene copolymer, Conjugated diene polymer latex such as methyl methacrylate-butadiene copolymer, acrylic polymer latex such as polymer or copolymer of acrylic acid ester and methacrylic acid ester, ethylene-
Vinyl-based polymer latexes such as vinyl acetate copolymers, modified polymer latexes containing functional groups such as carboxyl groups and cationic groups of these various polymers, synthetic resins such as thermosetting resins such as melamine resins and urea resins High-performance adhesives such as water-based adhesives, maleic anhydride copolymer resin-based, polyacrylamide-based, polymethylmethacrylate-based, polyurethane resin-based, unsaturated polyester resin-based, polyvinyl butyral-based, alkyd resin-based, etc. Since the molecule has good adhesiveness to the pigment or the base material and good affinity to the water-based ink, it improves the liquid absorbing property and is preferably used.

The proportion of the binder resin used in the ink-receptive coating layer is about 10 to 50% by weight, preferably 10 to 40% by weight, based on the total solid content of the coating layer. If it is less than 10%, the adhesive strength will be insufficient, and there is a concern that the strength of the coating layer will decrease. On the other hand, if it exceeds 50%, the adhesiveness increases, but the use ratio of the pigment decreases, and as described above, there may be a problem in the ink absorptivity.

Known coating equipment such as a bar coater, an air knife coater, a blade coater and a gravure coater can be applied to apply the coating material of the present invention. The sheet provided with the ink-receptive coating layer and the ink-fixing coating layer on the support can be used as it is as the recording sheet of the present invention. It is also possible to provide smoothness.

The coating amounts of the ink-receptive coating layer and the ink-fixing coating layer obtained in the present invention are not particularly limited and are determined according to the end use, and satisfy the ink absorbing property, the fixing property, the recording property storability and the like. There is no need to increase it unnecessarily. When paper is used as the ink-fixing coating layer, it is usually preferable that the total amount of both is about 3 to 110 g / m ² . In that case, the total amount is usually appropriately selected from the range of about 3 to 30 g / m ² and used. When the coating amount is small, the ink absorption capacity is often insufficient, and the image may run out,
Color bleeding may occur, the image may be blurred, the drying may be slow, and ink may be attached to the discharge roll of the printer to stain it. However, on the contrary, when the coating layer or coating layer is thick, the adhesiveness to the support is weakened, and the coating layer or coating layer that has peeled off often causes problems such as clogging of the head nozzle. Furthermore, it becomes expensive in terms of cost.

It is possible to add a layer structure such as providing a primer-treated layer on the support or forming each layer as a multi-layer.

[0032]

EXAMPLES The present invention will be described more specifically with reference to the following examples, but it should be understood that the present invention is not limited by these examples. In the following, parts and% mean parts by weight and% by weight. The coating amount is shown by dry weight.

Example 1 A polypropylene resin as a main component, an inorganic pigment and a small amount of additives such as stabilizers and dispersants were added and mixed, and after melt kneading with an extruder, a molten resin film was extruded thickly from a die / slit. After cooling once, it is heated to around the softening temperature again and stretched in the longitudinal and transverse directions to form a film, which is a synthetic paper having a multilayer structure YUPO FPG-110 (thickness 110
μm, made by Oji Oka Kasei Synthetic Paper Co., Ltd., is applied to one side of a coating material-1 at a rate of 8 g / m ² using a bar coater and dried to form a fixing coating layer. The coating material-2 was applied to the above at a rate of 9 g / m ² and dried to form a receptive coating layer, thereby producing an inkjet recording material.

Paint-1 75 parts of cellulose powder (trade name: KC Flock, manufactured by Sanyo Kokusaku Pulp) obtained by finely pulverizing wood cellulose by acid hydrolysis and mechanical treatment, SBR latex (trade name: 0617, 25 parts by Japan synthetic rubber).

Paint-2 75 parts of calcium carbonate (trade name: PC, manufactured by Shiraishi Kogyo),
Polyvinyl alcohol (trade name: 117, made by Kuraray) 2
5 copies.

Example 2 Multi-layered synthetic paper containing inorganic pigment, Yupo FPG-mentioned above
110 (thickness 110 μm, made by Oji Oka Kasei Synthetic Paper Co., Ltd.) was coated with paint-1 at a rate of 7 g / m ² using a test bar coater, dried to form a fixing coating layer, and similarly fixed. The coating material-3 was applied onto the functional coating layer at a rate of 8 g / m < ² > and dried to form a receptive coating layer, thereby producing an inkjet recording material.

Paint-3 75 parts of finely powdered synthetic silica (trade name: Fineseal, manufactured by Tokuyama), polyvinyl alcohol (trade name: 117,
25 made by Kuraray.

Example 3 A polypropylene resin as a main component, an inorganic pigment and a small amount of additives such as a stabilizer and a dispersant were added and mixed, and after melt-kneading with an extruder, a thick molten resin film was extruded from a die / slit. After cooling once, it is heated again to around the softening temperature, and stretched in the longitudinal and transverse directions to form a film, which is a synthetic paper YUPO FPG-95 (thickness 95 μm).
m, made by Oji Yuka Synthetic Paper) with a bar coater at a rate of 7 g / m ² using a bar coater and dried to form a fixing coating layer, and similarly on the fixing coating layer. Paint-3 on 8
The ink-jet recording material was manufactured by coating at a ratio of g / m ² and drying to form a receptive coating layer.

Paint-4 50 parts hardwood bleached kraft pulp slurry, 30 parts polyvinyl alcohol (trade name: 124, made by Kuraray), SB
R latex (trade name: 0617, made by Japan Synthetic Rubber) 2
0 copies.

Example 4 Multi-layered synthetic paper YUPO FPG-110 containing an inorganic pigment
(Thickness 110 μm, made by Oji Oka Kasei Synthetic Paper Co., Ltd.) On one side, paint-5 was applied at a rate of 5 g / m ² using a bar coater and dried to form a fixing coating layer, and similarly fixing coating was performed. Coating material-3 was applied on the layer at a rate of 7 g / m ² and dried to form a receptive coating layer, thus producing an inkjet recording material.

Paint-5 Microfibrillated cellulose (trade name: MFC, Daicel Chemical Industries, Ltd.) which is a high-purity natural cellulose whose surface area and pore volume are 50 to 100 times that of pulp by beating and refining. 40 parts, SBR latex (trade name: 0619, made by Japan Synthetic Rubber) 30 parts,
30 parts of polyvinyl alcohol (trade name: PVA105, made by Kuraray).

Example 5 Multi-layered synthetic paper YUPO FPG-110 containing an inorganic pigment
After coating a vinyl acetate emulsion adhesive (trade name: Cybinol GH-100, manufactured by Saiden Chemical Co., Ltd.) on one side of (thickness 110 μm, made by Oji Oka Synthetic Paper) with a bar coater at a rate of 15 g / m ^2. , Light calcium carbonate 20
Parts to a slurry of 100 parts of hardwood bleached kraft pulp, 0.8 parts of cationic starch, and 0.1 parts of emulsified alkenyl succinic anhydride neutral sizing agent (trade name: Fibran, manufactured by Oji National). Add and mix thoroughly to make a papermaking raw material, use a Fourdrinier cylinder paper machine to dry the water to 10%, and apply a 6% solution of oxidized starch on both sides with a size press at 5 g / m ² and dry. , A high-quality paper of 70 g / m ^{2 in} basis weight produced by drying to a water content of 7% (neutral paper having a thickness of 85 μm and having Steckigt size degree of 8 seconds and ash content of 12%) was laminated and dried. A fixing coat layer is formed, and a paint is also applied on the fixing coat layer using a bar coater.
Was coated at a rate of 10 g / m ² and dried to form a receptive coating layer, thus producing an inkjet recording material.

Comparative Example 1 Multi-layer synthetic paper containing inorganic pigment YUPO FPG-95 (thickness: 95 μm, made by Oji Yuka Synthetic Paper) was coated with 11 g / m of paint-2 using a test bar coater in a laboratory. ²
Was coated and dried to form a receptive coating layer, to produce an inkjet recording material.

Comparative Example 2 A synthetic paper YUPO FPG-95 (thickness: 95 μm, made by Oji Yuka Synthetic Paper) having a multilayer structure containing an inorganic pigment was coated on one side with a painter-3 at a rate of 10 g / m ² . An ink jet recording material was manufactured by coating and drying to form a receptive coating layer.

Comparative Example 3 Multi-layered synthetic paper YUPO FPG-95 (thickness: 95 μm, made by Oji Yuka Synthetic Paper) having a multi-layered structure containing an inorganic pigment was coated on one side with a bar coater to paint-6 (carboxy, which is a water-soluble cellulose derivative) (Containing methyl cellulose) at a rate of 8 g / m ² and dried to form an undercoat layer.
Was coated at a rate of 12 g / m ² and dried to produce an inkjet recording material. Paint-6 Carboxymethyl cellulose (trade name: CMC, manufactured by Daicel Chemical Industries) 60 parts, SBR latex (trade name:
0619, manufactured by Japan Synthetic Rubber) 30 parts, polyvinyl alcohol (trade name: 117, manufactured by Kuraray) 10 parts.

Comparative Example 4 Paint 7 was applied at a rate of 8 g / m ² using a bar coater on one surface of a synthetic paper YUPO FPG-95 (thickness: 95 μm, made by Oji Yuka Synthetic Paper) having a multilayer structure containing an inorganic pigment. An undercoat layer was formed by coating and drying, and then coating material-3 was coated and dried at a rate of 12 g / m ² to produce an inkjet recording material. Paint-7 Calcium carbonate (trade name: PC, manufactured by Shiraishi Industry) 70
Part, polyvinyl alcohol (trade name: 117, made by Kuraray) 30 parts.

Table 1 shows the evaluation results of these coated papers. The inkjet recording characteristics were evaluated by the following methods. Inkjet plotter (Design Jet)
650C: manufactured by Hewlett Packard), the ink absorbency, the vividness of color development, and the color bleeding were evaluated.

To evaluate the ink absorbency, the number of seconds until the printed ink dries was measured. 5 seconds or less ○, 6
-10 seconds is indicated by Δ, and 11 seconds or more is indicated by x.

The vividness of coloring is yellow, magenta,
The color development of the cyan color ink was visually evaluated. Good color development is ○, insufficient color is △, and poor color is ×.
Indicated by.

For the color bleeding, after printing red, blue and green, the bleeding was left for one week at room temperature, and the bleeding at the boundary of each color was visually evaluated. A sample with no bleeding was marked with a circle, a sample with a slight bleeding was marked with a mark, and a large amount of bleeding was marked with a mark.

[0051]

[Table 1]

As can be seen from Table 1, the ink jet recording materials obtained in the examples were very excellent in ink absorbency, vividness of color development, and color bleeding. However, the one using calcium carbonate instead of the fine powder synthetic silica in the ink receptive coating layer was slightly inferior in both ink absorbability and color development (Example 1). The ink jet recording material obtained in Comparative Example had poor color bleeding.

[0053]

INDUSTRIAL APPLICABILITY The ink jet printer recording material of the present invention not only excels in ink absorption and color development but also enables ink jet printing excellent in storage stability of printed matter.

Claims (3)

[Claims] 1. A support selected from a resin film and a synthetic paper is provided with an ink-fixing coating layer containing at least water-insoluble cellulose, and an ink-receiving coating layer containing a pigment and a resin is further laminated. Inkjet recording material. 2. The water-insoluble cellulose contained in the ink-fixing coating layer comprises cellulose pulp, cellulose powder,
The inkjet recording material according to claim 1, wherein the inkjet recording material is at least one selected from microfibrillated cellulose. 3. The ink jet recording material according to claim 1, wherein the ink fixing coating layer is paper.