JPH10226985A - Recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a recording medium that secures pictures of less blurs even in high-speed printing, has improved affinity with the printing ink, enables high-quality printing, and is suitable for the ink-jet printing system, etc., by providing a specific ink accepting layer on a substrate. SOLUTION: This recording medium comprises an ink accepting layer that is provided on one surface of a substrate, such as a polyester film, and is constructed of at least two layers of an ink absorbing layer and an ink penetrating layer which is laminated on the ink absorbing layer and is composed of sulfonate-containing resin particles and a binder, such as polyvinyl alcohol. The sulfonate-containing resin is preferably composed of one or more kinds of polyester or polyurethane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording material suitable for an ink jet recording system capable of expressing details. More specifically, the present invention relates to a recording material that can print with high quality with little bleeding even when printing at high speed.

[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 industrial fields such as large signboards is expected because of the improvement in printing quality and the ease of upsizing that approach silver halide photography. Printing by the inkjet method is greatly affected not only by the performance of the hardware but also by the properties of the recording material, and various recording materials have been developed. Among them, a so-called back print type recording material has been proposed in which an ink absorbing layer and an ink passing layer are laminated on a light-transmitting substrate, printed from the ink passing layer side, and viewed from the substrate side. Fair 5-50
396, 73586, 76435). In this method, since the viewing surface is from the base material side, uniform gloss is obtained, and a photographic image can be recorded. Further, when the ink passing layer is thin and has high transparency by this method, the recording material is less likely to cause blocking or the like. However, with the recent increase in printing speed, there has been a problem in that print quality is reduced. This is because the speed at which the ink passes through the ink passage layer is low, so that the ejected inks overlap and bleeding occurs.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a recording material adapted to the above-mentioned high-speed printing.
That is, an object of the present invention is to provide a recording material adapted to high-speed printing by improving the speed at which ink passes through the ink passage layer.

[0004]

The object of the present invention is to provide a recording material having at least two layers, an ink-absorbing layer and an ink-passing layer, laminated on one surface of a base material, wherein the ink-passing layer is a resin containing a sulfonate group, more preferably a sulfonate-containing resin. The problem can be solved by mainly comprising an acid-base-containing polyester or polyurethane particle and a binder. By using the ionic particles, it is possible to improve the affinity with the ionic ink, and it is possible to quickly pass the ink to the ink absorbing layer. As a result, an image with less bleeding can be printed even when printing at high speed.

Hereinafter, the present invention will be described in detail. In the present invention, the substrate is not particularly limited. For example, a polyester film, a polystyrene film, a polypropylene film, a plastic film such as acryl, paper, cloth, glass and any two or more of these materials are bonded together. One. When observing an image from the opposite side of the substrate on which the ink receiving layer is formed, it is preferable to use a substrate having a light transmittance of 80% or more, such as a polyester film, a polystyrene film, a polypropylene film, and an acrylic film. Plastic films, glass, and those obtained by laminating any two or more of these.

In the present invention, a recording material can be obtained by providing an ink receiving layer on such a substrate. The ink receiving layer is a layer capable of absorbing and retaining ink ejected from an inkjet recording type printer. The ink receiving layer may be a single layer, but is preferably composed of at least two layers, an ink absorbing layer and an ink passing layer.

The ink passage layer is a layer that absorbs ink jetted from an ink jet recording type printer and guides most of the ink to a lower ink absorbing layer. The ink passage layer is a layer that can absorb and retain ink that has passed through the ink passage layer.

The ink absorbing layer is not particularly limited as long as it has an ink absorbing ability, and may be either ink absorbing using a resin having ink absorbing properties or ink absorbing using a capillary phenomenon. When a resin having ink absorbency is used as a main component, any known resin having ink absorbency can be used, for example, polyvinyl alcohol, acrylic resin, styrene-acrylic polymer, ethylene-vinyl acetate polymer. , Starch, polyvinyl butyral, gelatin, casein, ionomer, gum arabic, carboxymethylcellulose, polyvinylpyrrolidone, polyacrylamide, polyester resin, styrene-butadiene rubber, and other modified resins. Preferably, it is polyvinyl alcohol. In this case, a known treatment for improving water resistance can be used if necessary.

In order to ensure excellent color developability and fixability even when pigment ink is used, it is effective to make the ink porous so as to have ink absorbability by capillary action. The layer is composed of particles and binder.
Examples of the particles include silica, kaolinite, talc, calcium carbonate, zeolite, alumina, barium sulfate, carbon black, zinc oxide, titanium oxide, benzoguanamine particles, crosslinked polystyrene, crosslinked acrylic particles, and aluminum hydroxide. The binder is not particularly limited, but includes polyvinyl alcohol, acrylic resin,
Resins such as styrene-acrylic polymer, ethylene-vinyl acetate polymer, starch, polyvinyl butyral, gelatin, casein, ionomer, gum arabic, carboxymethylcellulose, polyvinylpyrrolidone, polyacrylamide, polyester resin, styrene-butadiene rubber and the like and modifications thereof One or more of the resins can be used as desired. Preferably, it is polyvinyl alcohol which is a hydrophilic resin. The volume ratio between the particles and the binder is preferably from 1/1 to 1/10 from the relationship between the ink absorption capacity and the film strength. More preferably, it is 1/1 to 1/5.

Furthermore, 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 during coating, defoaming the coating solution, reducing 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. 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. 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. 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 lip coating method can be applied. The coating amount is not particularly limited, but is 5 g / m ² to 50 g / m ^2.
It is preferably ² . 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, a compound such as a polyester resin, a polyurethane resin, a polyester urethane resin, an acrylic resin, a melamine tree, and a mixture thereof can be used. 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.

The ink passage layer needs to have a property of promptly guiding the ink to the ink absorbing layer. For that purpose, it is necessary to make it mainly composed of particles and a binder and make it porous. As particles, it is necessary to select optimal particles in order to improve the passage of ink. The purpose of the ink passage layer is to allow ink to pass through, and it is necessary to reduce the ink holding capacity as much as possible. Therefore, it is preferable that the ink does not adsorb to the surface of the particles, and non-porous organic particles are preferable. Further, in order to improve the ink passing ability, those having ionic properties on the surface are preferable. Sulfonic acid group-containing resins that can have appropriate ionicity, more preferably sulfonic acid group-containing polyester or polyurethane particles, are most preferred. Further, for the purpose of adjusting the hiding power, light dispersibility, etc., silica, kaolinite, talc, calcium carbonate, zeolite, alumina, barium sulfate, carbon black, zinc oxide, titanium oxide, benzoguanamine particles, cross-linked polystyrene, cross-linked acrylic particles, Particles such as aluminum hydroxide may be mixed. The resin that binds the particles is preferably a resin that is hardly soluble in water. For example, a polyester resin, a polyacrylic resin, a polyurethane resin, a melamine resin, and various copolymers can be mentioned, and an acrylic resin and an acrylic / styrene copolymer, which absorb a small amount of water, are preferable.

[0014] It is preferable that the composition be mainly composed of particles and a binder for binding the particles. The ratio of particles to binder is preferably between 1/1 and 30/1. More preferably, it is 3/1 to 20/1. If the amount of particles is small, the gaps between the particles are filled, making it difficult for ink to pass through. Conversely, if the amount of particles is too large, the strength of the layer will decrease. Since the particle size also contributes to the passage of the ink, if it is too large, it causes bleeding of the ink, and if it is too small, the film becomes brittle. Therefore, a particle size of 0.5 to 5 μm is preferable.

It is preferable to add a surfactant, wax or the like to the ink passage layer in order to adjust the ink passage property. 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 deposited, 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 thickness of the ink passage layer varies depending on the use. When used as a back print, it is necessary to provide an appropriate concealing property, so that a certain thickness is required. Further, when not used as a back print, it is necessary to reduce the thickness so as not to have concealment. Therefore, 0.5 μm to 30 μm is preferable. The method of providing the ink passage layer is not particularly limited, but includes a gravure coat method, a kiss coat method, a dip method, a spray coat method, a curtain coat method, an air knife coat method, a blade coat method, a reverse roll coat method, and a bar coat method. For example, a commonly used method can be applied. 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.

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. Further, the ink used is an ink in which a water-soluble dye such as a direct dye, an acid dye or a food coloring is dissolved (a dye ink), and an ink in which a pigment is dispersed (a pigment ink).
Can be used. The recording material thus obtained has no bleeding even when printing at high speed and can express details.

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 Dye-type inkjet printer (ENC Co., Ltd.)
Printing was performed using ADVA NOVAJET PRO) and genuine ink.

2) Quality of Recorded Image An image in which 1/72 inch red lines were arranged in 10 lines at 1/72 inch intervals was printed using the above printer. At that time, the printing conditions were bidirectionally performed in four passes, and the injection rates were changed to 4000 Hz, 7000 Hz, and 10000 Hz. Visually check the quality of the recorded image
The evaluation was made in three stages of x. ：: Red lines are clearly expressed one by one. ×: The red line is not visible due to bleeding, and is expressed in a red solid image. △: between ○ and ×

The method for producing the polyester particles used in the present invention is described below. (Synthesis of polyester resin) In an autoclave equipped with a thermometer and a stirrer, 93 parts by weight of dimethyl terephthalate, 93 parts by weight of dimethyl isophthalate, 8 parts by weight of trimellitic anhydride, ethylene glycol Then, 159 parts by weight of toluene, 30 parts by weight of tricyclodecane dimethanol, and 0.1 part by weight of tetrabutoxy titanate were charged, and the mixture was heated at 180 to 230 ° C. for 120 minutes to perform a transesterification reaction. Then, the temperature of the reaction system was raised to 240 ° C., and the reaction was continued at a system pressure of 1 to 10 mmHg for 60 minutes, thereby obtaining a copolymerized polyester resin (A1). Table 1. Composition, glass transition temperature, specific gravity, molecular weight, melt viscosity, outflow starting temperature and softening temperature of the obtained copolymerized polyester resin (A1). Shown in The composition of the polyester was analyzed by NMR, the glass transition temperature was DSC, the specific gravity was the float-sedimentation method, the molecular weight was GPC, the melt viscosity was 120 ° C., the load was 10 kg / cm ² , and the thin tube diameter was 1 mm by Shimadzu Flow Tester CFT-500.
It was measured by a constant temperature method under the condition of a thin tube length of 10 mm. The outflow starting temperature and softening temperature are determined by Shimadzu Flow Tester CFT-
The measurement was performed under the conditions of a heating rate of 3 ° C./min, a load of 50 kg / cm ² , a capillary diameter of 0.5 mm, and a capillary length of 1.0 mm. The moisture absorption is a value measured by a Karl Fisher moisture content meter after leaving a coarsely pulverized resin powder at 30 ° C. and 95% RH for 72 hours.

Hereinafter, polymerization was carried out in the same manner by changing the raw materials. The following polyester resins (A2) to (A5) were obtained. Table 1. The abbreviations in it are shown below. TBBA: tert-butyl benzoic acid NDC: 1,5-naphthalenedicarboxylic acid TPA: terephthalic acid IPA: isophthalic acid SIP: sodium sulfoisophthalic acid TMA: trimellitic acid EG: ethylene glycol PG: propylene glycol CHD: cyclohexane Diol TCDD: Tricyclodecane dimethanol Tg: Glass transition temperature

(Production of Polyester Aqueous Dispersion) 340 parts by weight of polyester resin (A2), methyl ethyl ketone 1
50 parts by weight, 140 parts by weight of tetrahydrofuran at 80 ° C.
Then, 680 parts of water at 80 ° C. was added to obtain an aqueous microdispersion of a copolymerized polyester resin having a particle diameter of about 0.1 μm. Further, the obtained aqueous microdispersion was placed in a distillation flask and distilled until the fraction temperature reached 100 ° C. After cooling, water was added to adjust the solid concentration to 30%. This was designated as a polyester aqueous dispersion (E2). Hereinafter, polyester aqueous dispersions (E3) to (E5) were obtained from the polyester resins (A3) to (A5) in the same manner. The obtained polyester resin (A6) 100 was placed in a four-necked 10-liter separable flask equipped with a thermometer, a condenser, and a stirring blade.
0 parts by weight and 500 parts by weight of butyl cellosolve
Was dissolved. Then, 0.1 normal ammonia water 300
After adding 0 parts by weight and dispersing in water, the mixture was distilled in a distillation flask until the distillate temperature reached 100 ° C., and after cooling, water was added, and a polyester aqueous dispersion (E) having a solid concentration of 30% was added.
6) was obtained.

(Production of polyester spherical particles)
In a four-necked 1-liter separable flask equipped with a condenser and stirring blades, an aqueous polyester dispersion (E2) 3 was added.
00 parts by weight were charged and heated to 80 ° C. Next, 40 parts by weight of a 20% by weight aqueous solution of dimethylaminoethyl methacrylate was added over 60 minutes, and the mixture was further added for 80 minutes for 80 minutes.
Stirring was continued while the temperature was maintained at ° C. The conductivity in the system is about 1m
From S / cm increased to 25 mS / cm, pH decreased from 10.8 to 6.7. From this, it was inferred that the added dimethylaminoethyl methacrylate was almost completely hydrolyzed afterwards to form a salt of dimethylaminoethanol and methacrylic acid. The copolymer having a submicron-order particle size present in the polyester aqueous micro-dispersion grows as coalesced particles over time, and the average particle size is 6.5 μm.
Polyester spherical particles (P2) having an occupancy (number) of 95% of particles having a particle diameter in the range of 0.5D to 2D where m and diameter are D were obtained. The obtained polyester particles were filtered, washed with water, and dispersed again in water to obtain a solid content of 25% by weight.
Hereinafter, similarly, polyester spherical particles (P3) to (P5) were obtained from the aqueous polyester dispersions (E3) to (E5). Polyester particles (A1) are jet milled PJM200
The mixture was pulverized and classified by Nippon Nimatic Co., Ltd. and dispersed in water to obtain polyester particles (P1).

Example 1 Transparent polyester film (A41 manufactured by Toyobo Co., Ltd.)
(00 100 μm), the following ink absorbing layer and ink passing layer were formed 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 (GH-17, manufactured by Nippon Gohsei) 100 parts by weight Melamine resin (Sumimar M3, manufactured by Sumitomo Chemical Co., Ltd.) 15 parts by weight Cationic compound (Kayafix UR manufactured by Nippon Kayaku Co., Ltd.) 10 parts by weight Acrylic particles (Japan 150 parts by weight of an eposter MA1002 manufactured by Catalyst Co. Ink Passing Layer A coating solution having the following solid content ratio was bar-coated on the ink absorbing layer, and dried at 100 ° 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 parts by weight Polyester particles (A2) 50 parts by weight Silicone surfactant (Paintad 57 manufactured by Dow Corning) 2 parts by weight The recording medium thus obtained is It was white and opaque. Ink jet recording was performed on this recording medium.

Examples 2, 3, 4 In Example 1, the particles used for the ink passage layer were (A
3), (A4) and (A5), except that the recording material was obtained in the same manner as in Example 1. Comparative Example 1 The particles used for the ink passage layer in Example 1 were (A
A recording material was obtained in the same manner as in Example 1 except that 1) was used.

Description of Examples In Examples 1, 2, 3, and 4, since the polyester particles in the ink passage layer contained a sulfonate group, high-speed printing was possible. In Comparative Example 1, bleeding occurred when high-speed printing was performed because the polyester particles in the ink passage layer did not contain a sulfonate group.

[0028]

The present invention provides a recording material capable of expressing details in high-speed printing.

[0029]

[Table 1]

[0030]

[Table 2]

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

Claims (2)

[Claims] 1. A recording material having an ink receiving layer provided on one side of a substrate, wherein the ink receiving layer is composed of at least two layers in which an ink passing layer is laminated on the ink absorbing layer.
A recording material, wherein the ink passage layer is mainly composed of particles made of a sulfonate group-containing resin and a binder. 2. A recording material characterized in that the sulfonic acid group-containing resin according to claim 1 comprises at least one of polyester and polyurethane.