JPH1044586A - Ink jet recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To print a high quality image with high coloring density regardless of the physical properties of ink being used by forming an image observing face reversely to a print face where an ink receiving layer is provided on one side of a translucent basic material and setting the density of ink higher for the former than for the latter. SOLUTION: Preferably, an ink receiving layer comprises at least two layers, i.e., an ink absorbing layer and an ink passing layer. The ink absorbing layer is preferably composed of polyvinyl alcohol and waterproofness thereof must be enhanced. The ink passing layer is preferably porous and composed of particles and a binder. Organic particles absorbing no moisture are preferably employed and a water insoluble resin is preferably employed as the binder. A surfactant is preferably added to the ink passing layer. According to the arrangement, recording can be carried out with high coloring density regardless of the physical properties of ink and high quality recording can be carried out with high gloss.

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 paper having a different printing surface and an image viewing surface and having excellent water resistance.

[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 A printer using an ink jet system is a system in which ink droplets are ejected 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, the application to the industrial fields such as large signboards, posters, and illuminations is expected because of the improvement in printing quality and the ease of enlargement approaching silver halide photography. Although the target image quality of an ink jet printer is silver halide photography, the image quality is greatly affected by not only the performance of hardware but also the performance of recording paper, and a wide variety of recording papers have been developed. As an example, there is one having a high glossiness on the surface. However, there is a problem in that the glossiness of the ink-attached portion is reduced, and a recording medium for back printing in which a translucent ink image-receiving layer is formed on a transparent film has attracted attention. Since the surface of the recording medium used for the back print is a transparent film, there is no gloss reduction at the ink-attached portion, and an image similar to a silver halide photograph can be expressed by delicate light scattering inside the transparent film. Examples of the recording medium for inkjet used in back printing include (1) a coating layer formed of a large amount of inorganic particles and a water-soluble resin on a transparent film, and (2)
A film in which an ink image receiving layer and an ink passage layer are formed on a transparent film has been developed. However, the case (1) has drawbacks such as a problem that the water resistance of the ink-attached portion is reduced and a low color density. In (2), although the problem of water resistance of (1) was overcome, another problem occurs. The ink used for ordinary ink jet recording changes the physical properties of the ink depending on the manufacturer of the ink and the type of ink color. There is no particular problem when the ink is not used for back printing. In the case of the above (2), however, the permeation speed and permeation power of the ink passage layer vary due to the physical properties of the ink, particularly the surface tension, and the color balance is disturbed. There is a problem that the surface tension of the ink varies depending on the ink maker and the color development becomes poor. Further, in the case of an ink in which a pigment is dispersed (pigment ink), the pigment does not penetrate into the ink absorbing layer, and therefore, there is a problem of low color development. In general, it is necessary to match the ink and the recording medium of the recording medium, and it is necessary to develop a general-purpose type recording medium. That is, there is no ink jet recording medium used for back printing having a high color density without affecting the physical properties of the ink used in the ink jet recording method.

[0003]

SUMMARY OF THE INVENTION The present invention provides a high-quality recording by an ink jet printer, expresses a printing quality such as a silver halide photograph, and has a high color density without being affected by the physical properties of the ink used. It is an object of the present invention to provide an inkjet recording medium on which an image can be printed.

[0004]

The present invention is characterized in that the printing surface in which an ink receiving layer is provided on one side of a substrate and the image viewing surface are opposite, and the latter ink concentration is higher than the former ink concentration. It is assumed that. In the present invention, the substrate is not particularly limited as long as it has a light-transmitting property. Preferably, the substrate 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.

It is desirable that the ink receiving layer be composed of at least two layers: an ink absorbing layer and an ink passing layer. As the ink-absorbing layer, known resins can be used as long as they have ink-absorbing properties.
One or more resins such as ethylene-vinyl acetate polymer, starch, polyvinyl butyral, gelatin, casein, ionomer, gum arabic, carboxymethyl cellulose, polyvinyl pyrrolidone, polyacrylamide, polyester resin, styrene-butadiene rubber, and modified resins thereof. Can be used if desired. Preferably, it is polyvinyl alcohol.

[0006] The ink absorbing layer of the present invention must have improved water resistance. If the water resistance is poor, the interface between the ink-passing layer and the ink-absorbing layer is not clear, which causes poor coloring. Known methods can be used to improve the water resistance. Isocyanate, melamine, urethane,
A method for improving water resistance by adding a resin having a reactivity with an ink-absorbing resin such as epoxy. A method of improving water resistance by mixing a water-insoluble resin such as ethylene vinyl alcohol, completely saponified polyvinyl alcohol, polyamide, or polyethylene glycol, or a high molecular weight type resin. Improvement of water resistance by promoting crystallization by adding a nucleating agent, a plasticizer, and the like. Various methods such as improvement of water resistance by addition of fine particles having a large number of hydroxyl groups on the surface of silica, alumina, calcium carbonate, titanium oxide and the like can be used. Preferably, a water-soluble melamine resin is added as a curing agent. These are preferably added in an amount of 0.1 to 30% by weight based on the resin having ink absorbency. Further, in order to prevent the dye from bleeding or moving due to moisture such as moisture, the ink-absorbing resin 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.

A surfactant may be added to the ink absorbing layer for the purpose of improving leveling at the time of coating and defoaming the coating solution. 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. Examples of the silicone surfactant include dimethyl silicon, amino silane, acryl silane, vinyl benzyl silane, vinyl benzyl amino silane, glycid silane, mercapto silane, dimethyl silane, polydimethyl siloxane, polyalkoxy siloxane, hydrogen-modified siloxane, vinyl-modified siloxane,
Vitrooxy 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 and the like. . 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. These surfactants are preferably added to such an extent that the ink absorbing performance of the ink absorbing layer is not extremely reduced.

[0008] The ink absorbing layer may contain particles for improving winding and the like in manufacturing. Particles such as 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, and aluminum hydroxide can be added. preferable. 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, fluorescent dyes, plasticizers,
UV absorbers and the like. The method of providing the ink absorbing layer is not particularly limited. For example, a commonly used method can be applied. Although the coating amount is not particularly limited, it is 5 g / m ² to 30 g / m ^2.
Is preferred. By providing an anchor coat layer between the substrate and the ink absorbing layer, the adhesion between the substrate and the ink absorbing layer can be improved. As the compound constituting the anchor coat layer, a polyester resin is preferable,
In addition, compounds such as polyurethane resins, polyester urethane resins, acrylic resins, melamine tree species, and mixtures thereof can be applied. As a method of providing a coating layer, a gravure coat method, a kiss coat method,
Conventional methods such as a dip method, a spray coat method, a curtain coat method, an air knife coat method, a blade coat method, and a reverse roll coat method can be applied. It is preferable to provide an ink passage layer on the ink absorption layer.

The ink passage layer is mainly composed of particles and a binder, and is preferably porous. Particles such as 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. However, organic particles that do not adsorb moisture are preferred. The binder that binds the above particles is preferably a resin that is hardly soluble in water. For example, polyester resins, polyacrylic resins, polyurethane resins, melamine resins, and various copolymers can be mentioned, and a water-repellent acrylic resin that does not easily adsorb moisture and an acrylic / styrene copolymer are preferable. Preferably, the ratio of particles to binder is between 2/1 and 20/1. More preferably, it is 3/1 to 15/1. If the amount of the particles is small, the gap between the particles is filled, and it becomes difficult for the ink to pass through. Conversely, if the amount of particles is too large, the strength of the layer will decrease.

In the present invention, it is preferable to add a surfactant to the ink passage layer. Surfactants have effects such as leveling and defoaming when forming an ink passage layer,
In the present invention, the object can be achieved by adding an amount that cannot be considered in normal use. The purpose is to allow the ink adhering to the ink passage layer to pass through the ink passage layer and reach the ink absorbing layer. In the process, the surfactant is dissolved in the ink and the surface tension is reduced. With this effect, the ink passing effect can be improved, the amount of ink adhering to the ink passing layer can be reduced, the ink bleeding can be reduced, and a clear image with high color density can be obtained. Further, since the surface tension lowering effect of the surfactant stops at a certain amount without being proportional to the dissolution amount, even if the physical properties of the ink are different, the ink has the same physical properties during passage. This effect eliminates the need to design the recording medium to match the liquid properties of the ink, and any recording medium suitable for the ink whose surface tension has been reduced by the surfactant can be a versatile recording medium.

The surfactant is not particularly limited as long as it has a surface tension lowering effect, but a silicon-based surfactant and a fluorine-based surfactant are preferred. Silicon-based surfactants 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, vinyl-modified siloxane, and 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, and the like. As the fluorine-based surfactant, tetrafluoroethylene, perfluoroalkyl ammonium salt,
Perfluoroalkylsulfonic acid amide, sodium perfluoroalkylsulfonic acid, perfluoroalkylpotassium salt, perfluoroalkylcarboxylate, perfluoroalkylsulfonate, perfluoroalkylethylene oxide adduct, perfluoroalkyltrimethylammonium salt, perfluoroalkyl Examples thereof include an alkylaminosulfonic acid salt, a perfluoroalkyl phosphate, a perfluoroalkylalkyl compound, a perfluoroalkylalkylbetaine, and a perfluoroalkylhalide. 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. If it is 20% or more, there is a problem that the strength of the ink passage layer is reduced.

The method for 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, an air knife coating method, a blade coating method,
A commonly used method such as a reverse roll coating method or a bar coating method can be applied. The coating amount is not particularly limited, but it is preferable to provide a concealing property such that the pattern of the wall is not visible when the recording medium is attached to a wall or the like, and the light transmittance is 60% or less. Is preferred. To achieve this light transmittance, the coating amount after drying is 5 g /
It is preferably at least m ² . Conversely, if the coating amount is too large, the ink passage process becomes too long, resulting in poor color development. Therefore, the coating amount is preferably 20 g / m ² after drying. 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 include a layer containing an ultraviolet absorber and an antistatic agent, a hard coat for preventing scratches, a reduction in gloss, and the like. As a method of using the ink jet recording medium of the present invention, 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 ink-jet recording medium of the present invention may be any ink, and has good color development 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 inkjet recording medium of the present invention,
An ink in which a water-soluble dye such as a direct dye, an acid dye or a food dye is dissolved (a dye ink), and a water-based ink in which a pigment is dispersed (a pigment ink) are jetted by an ink jet recording apparatus and absorbed by an ink image receiving layer. Let it develop color,
It is used by appreciating from the substrate side. In the case of a dye ink, the dye enters the ink absorbing layer and develops a color. On the other hand, in the case of pigment ink, since the coloring pigment does not penetrate into the ink absorbing layer, the solvent in the ejected ink is absorbed by the ink absorbing layer, and the pigment gathers at the interface between the ink absorbing layer and the ink passing layer to form a color. I do. The ink jet recording medium of the present invention is excellent in coloring even with dye ink, but is particularly effective in coloring with pigment ink. The recording medium thus obtained should be capable of recording with high color density without affecting the physical properties of the ink used, and capable of recording with high gloss, high quality, and high quality such as silver halide photographs. became.

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. Recording method Pigment type inkjet printer (NOA Corporation)
Black black was printed using ESPRIT HA-1200 manufactured by Eisai Co., Ltd. and genuine ink. Dye type ink jet printer (ENCAD N)
OVAJETPRO) and genuine ink were used to print black solid. 2) Color density The black ink recording area was measured from the substrate side (B: image viewing side) and the ink application side (A: printing side) using a Macbeth densitometer TR-927. Quality of Recorded Image Several types of photographic images were recorded using the above-described two types of printers, and the quality of the recorded image was visually evaluated on a scale of △ ××. ：: 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 ×

Example 1 The following ink absorbing layer and ink passing layer were formed on a transparent polyester film (manufactured by Toyobo Co., Ltd., light transmittance: 89%) to obtain an ink jet recording medium. 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 10 g / m ² . Polyvinyl alcohol (Gohsenol GH-17, manufactured by Nippon Gohsei) 100% by weight Melamine resin (Sumimar M3, manufactured by Sumitomo Chemical) 15% by weight Cationic compound (Kayafix UR, manufactured by Nippon Kayaku) 10% by weight Ink passing layer Above ink absorbing layer Was coated with a coating solution having the following solid content ratio and dried at 120 ° C. for 1 minute. The coating amount at that time was 10 g / m ² . Acrylic resin (Accel reset 270E manufactured by Nippon Shokubai Co., Ltd.) 10% by weight Organic particles (Eposter MS manufactured by Nippon Shokubai Co., Ltd.) 90% by weight Silicon-based surfactant (Paintad 57 manufactured by Dow Corning) 5% by weight The resulting recording medium was white and opaque. Ink jet recording was performed on this recording medium.

Examples 2, 3, and 4 In Example 1, the amount of the surfactant in the ink passage layer was changed to 1, 1
An ink jet recording medium was obtained in the same manner as in Example 1 except that the content was 0 and 20% by weight.

Example 5 In Example 1, the surfactant in the ink-passing layer was changed to a fluorine-based surfactant (MegaFac F1 manufactured by Dainippon Ink KK)
An ink jet recording medium was obtained in exactly the same manner except that 42D) was used.

Comparative Example 1 An ink jet recording medium was obtained in exactly the same manner as in Example 1 except that the ink-passing layer contained no surfactant.

[0019]

Industrial Applicability The present invention provides a high-quality recording with an ink-jet printer, expresses printing quality such as silver halide photography, and has a high coloring density without being affected by the physical properties of the ink used. The purpose is to provide media.

[0020]

[Table 1]

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

Claims (3)

[Claims] 1. An ink-jet recording paper having an ink-receiving layer provided on one side of a light-transmitting base material, when printed on the recording medium using an aqueous ink, the color density of the printing surface (ink-receiving layer side). An ink jet recording medium, wherein the relationship between A and the color density B on the opposite surface (image viewing surface) is A <B. 2. The ink jet recording medium according to claim 1, wherein said ink receiving layer comprises an ink absorbing layer and an ink passing layer. 3. The ink-passing layer contains one or more surfactants.
4. The ink jet recording medium according to claim 3, wherein the content is not more than% by weight.