JPH10119419A - Recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To permit the expression of recording character, approached to a silver salt photograph, and make water-resistant treatment, such as lamination and the like, unnecessary after printing by a method wherein a ink receptive layer of a recording material is constituted of two layers of an ink absorbing layer and an ink passing layer while both of two layers are constituted of a porous layer. SOLUTION: A recording material is constituted of an ink absorbing layer 2 and an ink passing layer 3, which are laminated sequentially on a light passing substrate 1. Ink, given from a printer, is collided against the ink passing layer 2 and, finally, most of it is absorbed into the ink absorbing layer 3. The function of the ink absorbing layer 3 is to absorb ink, passed through the ink passing layer 2, quickly and, therefore, the ink absorbing power of the same should be higher than that of the ink passing layer 2. In order to provide with the function, the ink absorbing layer 3 is constituted of particles, having hydrophilic group such as hydroxide group and the like on the surfaces thereof, or constituted of particles having a large surface area and combining material principally and the layer 3 is made porous by increasing the amount of particles with respect to the combining material in the ratio of the volume. Ink absorbing capacity is retained by a capillary force due to the porosity.

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 film, and more particularly, to a film suitable for illumination.
The present invention also relates to an inkjet recording film capable of obtaining a high-quality image.

[0002]

2. Description of the Related Art In recent years, with the improvement of computer performance and the spread of computers, hard copy technology has rapidly developed. As a recording method of a hard copy, a method such as a sublimation transfer recording method, an electrophotographic method, and an ink jet method is known. 2. Description of the Related Art An ink jet printer is a method of printing characters, images, and the like on a recording material by ejecting ink droplets from nozzles toward recording paper at a high speed. In recent years, it has been rapidly becoming popular as a terminal for offices, homes, personal computers, and the like because of its ease of colorization and miniaturization and low printing noise. Furthermore,
From the improvement of printing quality approaching silver halide photography and the ease of enlargement,
It is expected to be applied to industrial fields such as large signboards. A variety of recording materials have been developed because the recording quality of an ink-jet printer largely depends on not only the performance of the hardware but also the performance of the recording material. Among them, recording media of the type with improved surface gloss can express a quality similar to silver halide photography, but when used for signboards etc. due to low water resistance, water resistant such as laminating a transparent film on the printed surface etc. Had to be treated. As a method for solving the problem, a recording material of a back print system has been developed (Japanese Patent Publication No. Hei 5-76435, Japanese Patent Publication No. Hei 5-7358).
6). The recording material of the back print method uses a recording material in which a translucent ink receiving layer is formed on a light transmitting base material,
This is a method in which an image is formed on an ink receiving layer and the viewing surface is on the side of a light-transmitting base material, and the above-described laminating effect is obtained by using a water-resistant thermoplastic resin or the like for the base material.
A conventional back-printing recording material has a translucent or opaque ink-receiving layer provided on a light-transmissive substrate, and the ink-receiving layer further comprises a water-soluble or water-swellable resin as a main component. A non-porous ink absorbing layer and a porous ink passing layer that does not absorb ink are laminated. In this configuration, since the water resistance of the ink absorbing layer is low, it cannot be used in places requiring complete water resistance such as outdoors unless the printed surface is subjected to a water resistance treatment such as lamination.

[0003]

The problem is that the water resistance of the printing surface of the recording material of the back print system is low, more specifically, the water film strength is low. (What is the water-resistant film strength?
The strength of the film when water is applied, and the one with low water-resistant film strength means that the film is removed by rubbing the coated surface when water adheres.) As a method for improving the water resistance of the printed surface, There are two types: (1) improvement of the water resistance of the ink passage layer and improvement of the water-resistant film strength (2) improvement of the water resistance of the ink absorption layer. First, (1)
According to the measure described above, improving the water resistance of the ink-passing layer can provide some film strength even if the lower ink-absorbing layer becomes flexible with water. Peel off at the interface of the absorbing layer. Further, the strength of the water-resistant film is improved by reducing the amount of cavities in the porous ink passage layer to improve the film strength. However, there is a problem that the print quality is deteriorated because the amount of cavities is reduced. Next, in the measure (2), since the ink absorbency and the water-resistant film strength are opposite properties, if the water-resistant film strength is improved, the ink absorbency is reduced, the ink bleeds, and the print quality is reduced. There's a problem. Accordingly, an object of the present invention is to provide a recording material capable of expressing a recording quality approaching that of a silver halide photograph, which does not require a water-resistant treatment such as lamination after printing.

[0004]

The object of the present invention is to provide an ink receiving layer of a recording material comprising two layers, an ink absorbing layer and an ink passing layer.
Further, it can be achieved by making both layers porous. Here, porous means that there are many fine voids in the film or on the surface, and that these voids include pores that lead to the outside.The voids absorb, hold, and pass the ink. Can be. An ink absorbing layer 2 and an ink passing layer 3 are sequentially laminated on a substrate having a light transmitting property 1 as shown in FIG. The ink applied from the printer strikes the ink passage layer, and is ultimately largely absorbed by the ink absorption layer (FIG. 2). The viewing surface is a transparent substrate on the side opposite to the surface on which the ink is applied. The function of the ink-absorbing layer is to quickly absorb the ink that has passed through the ink-passing layer, and the ink-absorbing power (the amount of ink held and the ink-absorbing speed) must be higher than that of the ink-passing layer. In order to have this function, it is mainly composed of particles having a hydrophilic group such as a hydroxyl group on the surface or particles having a large surface area and a binder, and the amount of particles is increased by volume ratio with respect to the binder to make the porous material porous. To The ink absorbability is provided by the capillary force of the porous material. Further, in order to increase the strength of the water-resistant film, it is necessary that the binder for binding the inorganic particles is not water-soluble and is a resin having low or no water swellability.

[0005] The function of the ink passage layer is to allow the ink to pass through without bleeding, and it is necessary to guide the ink to the lower layer without absorbing the ink. In order to provide this function, it is preferable that the organic particles are made of organic particles having a small surface area and a binder to be porous.

The present invention will be described in more detail below. In the present invention, the substrate is not particularly limited as long as it is light-transmitting, but preferably has a light transmittance of 80% or more. For example, a polyester film, a polystyrene film, a polypropylene film, a plastic film such as acryl, a glass, and a film obtained by laminating any two or more of these films are used. In the present invention, an ink jet recording medium can be obtained by providing an ink receiving layer on such a substrate. The ink receiving layer has at least two of an ink absorbing layer and an ink passing layer.
It is desirable to be composed of layers.

It is necessary that the ink absorbing layer be made of particles and a binder to be porous. Although the ratio of the particles to the binder is not particularly limited, the volume ratio is 1/1 in order to quickly absorb the ink and have a film strength.
〜1 / 10 is preferred. As the particles, particles having a certain degree of hydrophilicity and a high surface area are preferred. In order to increase the color density from the viewing surface side, it is preferable that the refractive index is close to that of the binder. For example, silica, kaolinite, talc, calcium carbonate, zeolite, alumina,
Barium sulfate, carbon black, zinc oxide, titanium oxide, organic white pigments, benzoguanamine particles, cross-linked polystyrene, cross-linked acrylic particles, particles such as aluminum hydroxide, and the like, but various balanced inorganic particles such as silica are preferable. The particle diameter is preferably 20 μm or less in order to reduce bleeding.

As the binder, those which are hydrophilic and water-insoluble are preferred. For example, polyvinyl alcohol, acrylic resin, styrene-acryl polymer, ethylene-vinyl acetate polymer, starch, polyvinyl butyral, gelatin, casein, ionomer, gum arabic, carboxymethyl cellulose, polyvinyl pyrrolidone, polyacrylamide, polyester resin, styrene-butadiene One or more of resins such as rubber and modified resins thereof can be used if desired. Preferred are polyvinyl alcohol and ethylene-vinyl acetate polymer which have been subjected to a water resistance treatment.

It is desirable for the ink absorbing layer to improve the film strength and the water resistance. A known method can be used as the method. A method of crosslinking the binder with isocyanate, melamine, urethane, epoxy, or the like can be used. Further, the resin used as the binder for preventing the dye from bleeding or moving due to moisture such as moisture preferably has a cationic group or an anionic group. If not, it is preferable to mix ionic resins and compounds. As a result, the ink absorbing ability can be improved, and the dye in the ink can be fixed in the ink absorbing layer.

[0010] A surfactant may be added to the ink absorbing layer for the purpose of improving leveling during coating, defoaming the coating solution, further improving absorption speed, preventing bleeding, and the like. The surfactant may be any of a cationic type, an anionic type, a nonionic type and a nonionic type. However, silicone-based or fluorine-based surfactants are preferred. Dimethyl silicon as a silicon-based surfactant,
Amino silane, acrylic silane, vinyl benzyl silane, vinyl benzyl amino silane, glycid silane,
Mercaptosilane, dimethylsilane, polydimethylsiloxane, polyalkoxysiloxane, hydrogen-modified siloxane, vinyl-modified siloxane, vitroxy-modified siloxane, amino-modified siloxane, carboxyl-modified siloxane, halogen-modified siloxane, epoxy-modified siloxane, methacryloxy-modified siloxane, mercapto-modified Examples include siloxane, fluorine-modified siloxane, alkyl group-modified siloxane, phenyl-modified siloxane, and alkylene oxide-modified siloxane. Examples of the fluorine-based surfactant include ethylene tetrafluoride, perfluoroalkyl ammonium salt, perfluoroalkyl sulfonamide, sodium perfluoroalkyl sulfonate, perfluoroalkyl potassium salt, perfluoroalkyl carboxylate, perfluoroalkyl sulfone Acid salt, perfluoroalkylethylene oxide adduct, perfluoroalkyltrimethylammonium salt, perfluoroalkylaminosulfonate, perfluoroalkylphosphate, perfluoroalkylalkyl compound, perfluoroalkylalkylbetaine, perfluoroalkylhalide, etc. Is mentioned.

Various additives may be added to the ink absorbing layer to such an extent that the ink absorbing ability and other physical properties are not impaired. For example, a fluorescent dye, a plasticizer, an ultraviolet absorber and the like can be mentioned.

The method of providing the ink absorbing layer is not particularly limited, but includes a gravure coating method, a kiss coating method, a dip method, a spray coating method, a curtain coating method, an air knife coating method, a blade coating method,
A commonly used method such as a reverse roll coating method, a bar coating method, and a die coating method can be applied. Although the coating amount is not particularly limited, it is 5 g / m ² to 30 g / m ^2.
It is preferred that When the adhesion between the substrate and the ink absorbing layer is insufficient, it is necessary to provide an anchor coat layer. As the anchor coat layer, polyester resin, polyurethane resin, polyester urethane resin,
Compounds such as acrylic resins and melamine tree species and mixtures thereof can be applied. As a method for providing the coating layer, a commonly used method such as a gravure coating method, a kiss coating method, a dip method, a spray coating method, a curtain coating method, an air knife coating method, a blade coating method, and a reverse roll coating method can be applied.

In the present invention, it is necessary to provide the ink passage layer on the ink absorption layer. The ink passage layer needs to be made porous from particles and a binder. The ratio of the particles to the binder is not particularly limited, but is 1/1 to 1 in volume ratio.
/ 20 is preferable. As the particles, those which do not adsorb the moisture and dye in the ink on the surface are good, and particles having a small amount of a hydrophilic group such as a hydroxyl group on the surface and particles having a small surface area are preferable. Further, particles that improve the concealability of the recording material and have high light scattering properties are preferred. Further, in order to reduce lateral bleeding, the particle size is preferably 10 μm or less. For example, silica, kaolinite, talc, calcium carbonate, zeolite, alumina, barium sulfate, carbon black, zinc oxide, titanium oxide, organic white pigments, benzoguanamine particles, crosslinked polystyrene, crosslinked acrylic particles, particles of aluminum hydroxide, etc. Be mentioned. Among them, benzoguanamine particles balanced with respect to the above functions are preferable.

The resin used as the binder is preferably a resin which is hardly soluble in water. For example, polyester resin, polyacrylic resin, polyurethane resin,
Melamine resins, ethylene vinyl acetate resins, polyvinyl alcohols, and various copolymers are exemplified, and acrylic resins and acrylic / styrene copolymers, which absorb a small amount of water, are preferred.

The ink passing layer has an improved ink passing speed,
It is preferable to add a surfactant, wax or the like in order to reduce the ink fixing ability and reduce bleeding. In particular, a silicon-based surfactant and a fluorine-based surfactant capable of lowering the surface tension of water are preferable. Surfactants can be present in the passage layer not only to reduce the amount of ink attached, but also to dissolve in the ink and reduce the surface tension of the ink. This effect can reduce the influence of the ink absorbency due to the surface tension of the ink. Further, the improvement of the ink passage property also serves to reduce the bleeding of the ink.

Examples of the silicone-based surfactant include dimethyl silicon, amino silane, acrylic silane, vinyl benzyl silane, vinyl benzyl amino silane, glycid silane, mercapto silane, dimethyl silane, polydimethyl siloxane, polyalkoxy siloxane, hydrogen-modified siloxane, and vinyl-modified. Siloxane, vitroxy modified siloxane, amino modified siloxane, carboxyl modified siloxane, halogenated modified siloxane, epoxy modified siloxane, methacryloxy modified siloxane, mercapto modified siloxane, fluorine modified siloxane, alkyl group modified siloxane, phenyl modified siloxane, alkylene oxide modified siloxane, etc. No. Examples of the fluorine-based surfactant include ethylene tetrafluoride, perfluoroalkyl ammonium salt, perfluoroalkyl sulfonamide, sodium perfluoroalkyl sulfonate, perfluoroalkyl potassium salt, perfluoroalkyl carboxylate, perfluoroalkyl sulfone Acid salt, perfluoroalkyl ethylene oxide adduct, perfluoroalkyl trimethyl ammonium salt,
Perfluoroalkylaminosulfonate, perfluoroalkylphosphate, perfluoroalkylalkyl compound, perfluoroalkylalkylbetaine,
And perfluoroalkyl halides.
Although the content varies depending on the type of the surfactant, the content is preferably 1 to 20% by weight based on the solid content of the ink passage layer. If it is less than 1%, the effect is not obtained. 20%
In such a case, there is a problem that the strength of the ink passage layer is reduced.

The method of providing the ink passage layer is not particularly limited, but includes a gravure coating method, a kiss coating method, a dip method, a spray coating method, a curtain coating method, a knife coating method, a blade coating method, a reverse roll coating method, A commonly used method such as a bar coating method and a die coating method can be applied. The coating amount after drying is preferably 3 g / m ² or more and 30 g / m ² or less. The surface of the substrate on which the ink image receiving layer is not provided can be subjected to various kinds of processing unless the light transmittance is extremely reduced. Examples of the layer include a layer containing an ultraviolet absorber and an antistatic agent, a hard coat for preventing scratches, a mat treatment, prevention of irregular reflection, and provision of various patterns.

The method of using the recording material of the present invention is such that the ejected ink is absorbed by the ink image receiving layer to form a color, and is viewed from the base material side. The ink used for the recording material of the present invention may be any ink, and the color development is good without being affected by the surface tension and viscosity of the ink. As a solvent in the ink, water is preferably a main component. As a method of using the recording material of the present invention, an ink (a dye ink) in which a water-soluble dye such as a direct dye, an acid dye or a food color is dissolved, and an aqueous ink (a pigment ink) in which a pigment is dispersed are used in an ink jet recording apparatus. The ink is used by being ejected, absorbed by the ink image receiving layer to form a color, and viewed from the substrate side. In the recording material of the present invention, after the applied ink passes through the ink passage layer, it is fixed by the ink absorption layer. If the conventional ink absorbing layer is non-porous,
When printing using a pigment ink, the pigment contributing to color development cannot penetrate into the ink absorbing layer, so that there are many pigments in the surface layer of the ink absorbing layer, in other words, the lower layer of the ink passing layer. Become. On the other hand, in the recording material of the present invention, even when pigment ink is used, a coloring pigment is fixed in the ink absorbing layer. As a result, a printed matter having a high color density can be produced even when the pigment ink is used. The recording medium thus obtained had high water-resistant film strength and high-quality, high-quality recording such as silver halide photography.

Examples Next, examples of the present invention and comparative examples will be described. First, a measurement / evaluation method used in the present invention will be described below. 1) Recording method Printing was performed using a dye-type inkjet printer (HP-750C, manufactured by Hewlett-Packard Japan Limited) and genuine ink. Printing was performed using a pigment type inkjet printer (RJ-1300 manufactured by Mutoh Kogyo KK) and genuine ink.

2) Color Density Black solid was printed using the printer described above, and the black ink recording area was measured from the substrate side (A) and the ink application side (B) using a Macbeth densitometer TR-927.

3) Quality of Recorded Image Several types of photographic images were recorded by using the above-mentioned printer, and the quality of the recorded image was visually evaluated on a scale of three (3). ：: A clear image similar to a clear silver halide photograph, which is expressed in detail without bleeding, etc. ×: A photographic image in which detail is not expressed due to bleeding and is not clear △: Intermediate between ○ and ×

4) Strength of Water-Resistant Film After the recording material was immersed in water for 5 minutes, the ink-receiving layer was rubbed with a finger, and evaluated on a three-point scale. ：: No scratches even when rubbed strongly. Δ: Scratched when strongly rubbed, but not when rubbed lightly. ×: Scratches are found even when rubbed lightly.

5) Existence position of pigment The cross section was observed with an optical microscope, and the colored layer was examined. Further, the existing position of the pigment was directly observed using an electron microscope. When the pigment was present inside the ink absorbing layer, it was evaluated as 、, and when the pigment was not present inside the ink absorbing layer, and was present at the interface between the ink passing layer and the ink passing layer and the ink absorbing layer, it was evaluated as ×. .

Example 1 A recording material was obtained by forming the following ink absorbing layer and ink passing layer on a transparent polyester film (manufactured by Toyobo Co., Ltd., light transmittance: 89%). Ink absorbing layer A coating solution having the following solid content ratio was bar-coated, and 12
It dried at 0 degreeC for 5 minutes, and formed the absorption layer. The dry coating amount at this time was 15 g / m ² . Polyvinyl alcohol (GH-17, manufactured by Nippon Synthetic Chemical Company) 100 parts by weight Melamine resin (8% AC, manufactured by Sumitomo Chemical Co., Ltd.) 10 parts by weight Cationic compound (Kayafix UR manufactured by Nippon Kayaku Co., Ltd.) 10 parts by weight Synthetic silica (Fuji 200 parts by weight Silysia 550) 200 parts by weight Silicon-based surfactant (Paintad 57 from Dow Corning) 3 parts by weight Dry for 1 minute. The coating amount at that time was 10 g / m ² . 10 parts by weight of acrylic resin (Acreset 270E manufactured by Nippon Shokubai Co., Ltd.) 100 parts by weight of organic particles (Eposter MS manufactured by Nippon Shokubai Co., Ltd.) 5 parts by weight of silicon-based surfactant (Paintad 57 manufactured by Dow Corning Co., Ltd.) 5 parts by weight The recording material was white and opaque.
Ink jet recording was performed on this recording material.

Comparative Example 1 A recording material was obtained in the same manner as in Example 1 except for the ink absorbing layer. Ink absorbing layer A coating solution having the following solid content ratio was bar-coated, and 12
It dried at 0 degreeC for 5 minutes, and formed the absorption layer. The dry coating amount at this time was 20 g / m ² . Polyvinyl alcohol (GH-17, manufactured by Nippon Gohsei) 100 parts by weight Melamine resin (8% AC, manufactured by Sumitomo Chemical Co., Ltd.) 10 parts by weight Cationic compound (Kayafix UR, manufactured by Nippon Kayaku Co., Ltd.) 10 parts by weight Silicon-based surfactant 3 parts by weight of agent (Paintad 57 manufactured by Dow Corning)

Comparative Examples 2, 3, 4 A recording material was obtained in the same manner as in Comparative Example 1 except that the amount of the melamine resin was 7, 3, and 0 parts by weight.

Comparative Example 5 A commercially available recording material for back printing (BF manufactured by Canon Inc.)
-102) was used.

[0028]

According to the present invention, a recording material having high quality in recording by an ink jet printer, expressing printing quality such as silver halide photography, and having high water-resistant film strength can be obtained.

Description of Example In Example 1, the print quality was good because the ink absorbing layer was porous and had a high ink absorbing ability. Furthermore, the water-resistant film strength was good because the binder was polyvinyl alcohol crosslinked with a melamine resin. Comparative Example 1
The water absorption film strength was good because the ink absorbing layer was highly crosslinked with melamine, but the ink absorption ability was reduced due to the high crosslinking, and the image quality was poor due to ink bleeding and the like. Comparative Example 4 has high ink absorbing ability and good image quality because it is not crosslinked, but has poor water resistant film strength because of a low degree of crosslinking. In Comparative Examples 2 and 3, although the amount of the melamine as the cross-linking agent was set between Comparative Example 1 and Comparative Example 4, the image quality and the waterproof film strength were not compatible. Comparative Example 5 was commercially available, and the image quality was good, but the water resistant film strength was not satisfactory. Further, the coloring density was also poor. When printing was performed with the pigment ink, only Example 1 contained the pigment up to the ink absorbing layer. All the comparative examples stopped at the ink passage layer.

[0030]

[Table 1]

[Brief description of the drawings]

FIG. 1 shows an example of a laminated structure according to the present invention.

FIG. 2 shows a process in which ink is absorbed.

[Explanation of Codes] 1. ink passage layer 2. ink absorption layer Light transmissive substrate

 ──────────────────────────────────────────────────の Continued on front page (72) Inventor Toshitake Suzuki 2-1-1 Katata, Otsu City, Shiga Prefecture Toyobo Co., Ltd. Research Laboratory

Claims (6)

[Claims] 1. A recording material comprising an ink-absorbing layer and an ink-passing layer laminated on one surface of a light-transmitting substrate, wherein both the ink-absorbing layer and the ink-passing layer are porous. . 2. A recording material according to claim 1, wherein said ink absorbing layer mainly comprises inorganic particles and a binder. 3. A recording material according to claim 1, wherein said ink passage layer mainly comprises organic particles and a binder. 4. A recording material characterized in that the ink absorbing layer according to claim 1 contains a cationic resin. 5. The recording material according to claim 1, wherein the relationship between the color density A measured from the ink-applied surface side and the color density B measured from the light transmitting base material is A <B. Wood. 6. The ink absorbing layer according to claim 1, wherein the pigment enters the ink absorbing layer when printed with the pigment ink.
Any of the recording materials.