JP2000211236A - Recording sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording sheet of an excellent absorption property relative to water soluble ink in ink jet recording, and having an acceptable layer of no blocking or set off of ink even when a base material film, paper or the like is superimposed for the short period of time after printing. SOLUTION: The recording sheet 1 includes an acceptable layer 3 set on at least one surface of a base material sheet 2, and the acceptable layer 3 is a single layer or a multilayer of two or more layers; in any ways, since protein is included in the acceptable layer (at least one layer), an excellent water absorptivity is achieved, and the surface of the acceptable layer 3 becomes fine uneven, so that even then the base film, paper or the like is superimposed with the surface of the acceptable layer 3 for the short period of time after printing, there is no blocking or set off of ink. Also, the acceptable later 3 is preferably be formed and cured applying a composition containing a hydrophilic monomer and/or oligomer of an ionizing radioactive ray curing type with a more improved performance such as water resistance and an antiabrasion property, and irradiating ionized radioactive rays, as a results, an acceptable layer can be formed readily because acceptable later 3 is cured for short period of time by irradiating an electrolytic radioactive rays.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium having a receptive layer which is excellent in absorptivity for water-based ink and has no blocking or show-through of ink even when a base film or paper is overlapped in a short time after printing. It relates to a sheet for use.

[0002]

2. Description of the Related Art Conventionally, as an output print of a computer or a word processor, a wire dot recording system,
Various systems such as a thermosensitive coloring recording system, a thermosensitive transfer recording system, a thermosensitive sublimation transfer recording system, an electrophotographic recording system, and an ink jet recording system have been developed. Among them, the ink jet recording method has the features that plain paper can be used as a recording sheet, printing cost is low, the apparatus is compact, there is no noise, and high-speed recording is possible. For this reason, attention has been paid to the use as a printer for quickly and accurately outputting image information such as characters and figures produced by a computer or the like. Also,
Because it is easy to colorize and the pattern is clear, it is necessary to record computer-generated image information on a transparent recording sheet with an inkjet printer and use this as a manuscript of OHP etc. at conferences, presentations at various conferences, etc. Is also growing.

In general, an ink jet printer ejects recording ink from a nozzle by pressure of a fine piezoelectric element (piezo element) or air pressure (bubble jet) generated by heating a thermal head, and adheres to a recording sheet. The recording is performed by causing the recording. For this reason, as a recording ink used for ink jet recording, an ink that is difficult to dry is used in order to prevent ink ejection failure from nozzles due to an increase in viscosity due to drying of the ink. In general, the ink component generally has a dye, a polymer, an additive, and the like dissolved in water and alcohol. Therefore, a recording sheet on which recording is performed by an inkjet printer is required to absorb the liquid component of the attached ink and dry and solidify the ink. For this reason, a recording sheet in which an ink receiving layer is formed on a base sheet to enhance ink absorption is used.

In particular, the ink receiving layer of a recording sheet for an ink jet printer is required to have the following characteristics. Drying property: Excellent ink absorbency and fast ink drying property. Image clarity: An appropriate dot spread is obtained, and a clear image without blur is obtained. Transparency: Haze (haze value) is not large. Antistatic property: Does not cause adhesion of dust or double feeding of sheets due to electrification. Preservability: No deterioration in image clarity after storage at high temperature and high humidity, and no blocking in which sheets adhere to each other. Curling resistance: The recording sheet including the ink receiving layer does not curl in the use environment. From such a viewpoint, a conventional recording sheet includes an ink receiving layer on a base sheet, and as the receiving layer, those using a water-soluble resin, those using a water-absorbing resin, and the like have been devised. .

[0005]

It has been proposed to use a large number of water-soluble or water-absorbing polymers for the receiving layer of an ink jet recording sheet. For example, it has been proposed to provide a receiving layer using polyvinyl alcohol, starch, gelatin, cellulose derivatives such as hydroxyethylcellulose and methylcellulose, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid and salts thereof. However, these methods have problems in that a sufficient ink absorption rate cannot be obtained, causing bleeding of a printed image, a receptor layer being dissolved in water and disappearing, and stickiness of a printing surface being generated. Was.

As described above, the conventional recording sheet is excellent in the absorbency and drying property of the water-based ink, and is also excellent in the fastness such as water resistance, and has not been able to satisfy all of these functions. Is the current situation. The present invention has been made in view of such circumstances, and its object is to have excellent absorptivity and the like for aqueous inks in inkjet recording,
An object of the present invention is to provide a recording sheet having a receptor layer free from blocking or show-through of ink even when a base film, paper, or the like is overlaid in a short time after printing.

[0007]

In order to achieve the above object, the present invention provides a recording sheet having a receiving layer provided on at least one side of a base sheet, wherein the receiving layer contains protein particles. . Further, in a recording sheet having a receiving layer provided on at least one surface of a base sheet, the receiving layer is a multi-layer of two or more layers, and at least one of the multi-layers contains protein particles. The receiving layer is preferably formed by applying a composition containing an ionizing radiation-curable hydrophilic monomer and / or oligomer, irradiating the composition with ionizing radiation, and curing the composition. In addition, the receiving layer composed of multiple layers described above is obtained by applying at least one layer of the receiving layer to a composition containing a hydrophilic monomer and / or oligomer of an ionizing radiation-curable type and irradiating with an ionizing radiation to cure the composition. Preferably, it is formed.

The operation of the recording sheet of the present invention is as follows. The recording sheet is provided with a receiving layer on at least one side of the base sheet, and the receiving layer is a single layer or a multi-layered structure of two or more layers.
Because it contains protein particles (at least in one layer), it is excellent in water absorption, the surface of the receiving layer becomes fine irregularities, and even if the receiving layer surface and the substrate film or paper are overlapped for a short time after printing, No blocking or ink show-through. The receiving layer is preferably formed by applying a composition containing an ionizing radiation-curable hydrophilic monomer and / or oligomer, irradiating the composition with ionizing radiation, and curing the composition. And the like, and the receiving layer is cured in a short time by irradiation with ionizing radiation, so that the receiving layer can be easily formed.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing one embodiment of the recording sheet of the present invention. In FIG. 1, a recording sheet 1 is a base sheet 2
And a receiving layer 3 formed on one surface of the base sheet 2. (Base Sheet) As the base sheet 2 used in the recording sheet of the present invention, the same base sheet as used in conventional recording sheets can be used as it is, and other base sheets can also be used. And is not particularly limited. Polyolefin, polystyrene etc. synthetic paper, high quality paper, art paper, coated paper, cast coated paper,
Various colored or white papers such as wallpaper, backing paper, synthetic resin impregnated paper, emulsion resin impregnated paper, synthetic rubber latex impregnated paper, synthetic resin internal paper, paperboard, and the like, base materials for labels, plastic films and the like can be mentioned. Further, a composite base material in which two or more of these materials are bonded together is also used. The thickness of these substrate sheets is appropriately selected in consideration of the strength and the like depending on the application, and is not particularly limited.
Usually, it is about 50 to 200 μm.

The plastic film is preferably formed of a thermoplastic having heat resistance, dimensional stability and rigidity. For example, polyethylene terephthalate resin, polycarbonate resin, acrylic resin, polyvinyl chloride resin, polypropylene resin, polystyrene resin, polyvinyl alcohol resin, polyethylene resin,
The thickness of diacetate resin, triacetate resin, polyimide resin, etc. is about 5 to 250 μm, preferably 50 to 18 μm.
A film or plate having a thickness of about 0 μm may be used. In particular, when used for an overhead projector (OHP), a transparent substrate sheet is used even for these plastic films.

[0011] The transparent base sheet has transparency,
Those formed of polyolefin having dimensional stability and low cost are preferable. For example, thickness 5 of polyethylene, polypropylene, poly (4-methyltenpen), etc.
A film or plate having a thickness of about 250 μm to about 250 μm, preferably about 50 to 180 μm can be used. OH
Opaque plastic films and papers are used for applications that do not require transparency other than P applications. Further, one or both surfaces of the base sheet may be subjected to a corona discharge treatment or an easy adhesion treatment as necessary. Further, an anti-curl layer may be provided on the surface of the base sheet on which the receiving layer is not formed. Alternatively, forming receiving layers on both surfaces of the base sheet is also effective as curling prevention.

(Primer Layer) When a receiving layer, an anti-curl layer, and the like are provided on a substrate sheet, a primer layer can be provided in order to improve the adhesion between those layers and the substrate sheet. The primer layer is not limited as long as it is a resin having an adhesive property, but it is not limited to polyester, chlorinated polyolefin, vinyl acetate-acryl copolymer, acrylate-vinyl acetate copolymer, acrylate-styrene. Polymer, olefin-vinyl ester copolymer, polyvinyl alkyl ether, alkylene-
Those containing polymers such as acrylonitrile copolymers and nitrile rubbers are preferred. In order to improve the adhesion of the primer layer and the strength of the coating film, a crosslinking agent such as polyisocyanate or phenol may be added to the polymer at a ratio of 1 to 50% by weight.

The above-mentioned primer layer may be formed by various known methods such as gravure coating, gravure reverse coating, roll coating, wire bar coating, blade coating, knife coating, air knife coating, comma coating, and the like. Any method such as slot die coating and dip coating may be used. Add an additive to the resin constituting the primer layer as necessary, coat the base sheet with a solution dissolved or dispersed in an appropriate solvent,
After drying, a primer layer is provided. The thickness of the primer layer is 0.01 to 50 μm, preferably 0.0
The thickness is preferably 5 to 10 μm. This thickness is 0.05μ
When the thickness is less than m, sufficient performance cannot be exhibited in the adhesiveness. On the other hand, when the thickness exceeds 10 μm, the end face becomes sticky at the time of cutting the recording sheet.
Not preferred.

(Receiving Layer) The receiving layer 3 is provided on at least one surface of the base sheet. The receiving layer is a single layer or a multi-layer of two or more layers.
Contains protein particles (at least in one layer).
When the receiving layer is composed of two or more layers, the layer containing protein particles may be on the substrate sheet side or the outermost surface side, but is preferably provided on the substrate sheet side. That is, a layer with surface irregularities is first formed on the substrate sheet side, and a receiving layer is further provided so as to cover the layer, to reduce the intensity of the outermost surface irregularities of the final form of the recording sheet, This is because blocking and show-through of the ink can be prevented, and an excellent image clarity can be obtained.

The protein particles are powdery protein fibers, and preferably have an average particle size of about 0.05 to 10 μm. If the particle size is too small, blocking or show-through of the ink is likely to occur when the receiving layer surface after printing and the base film or paper are overlapped, while if the particle size is too large, the unevenness of the receiving layer surface will be reduced. It's too big, the print image is rough,
Clarity becomes insufficient. Also, the protein particles are about 10 to 250% by weight based on the binder resin of the receiving layer.
It is preferable to add them at a ratio of about. If the added amount is small, the intended function cannot be sufficiently exhibited, while if the added amount is too large, the printed image becomes rough and the sharpness becomes insufficient. Protein particles are protein particles that are polypeptides having a molecular weight of 10,000 or more in which L-α-amino acids are polycondensed by dehydration between their amino groups and carboxy groups. In the present invention, collagen particles that are hard proteins can also be used as protein particles. Collagen is a fibrous form in which three polypeptide chains having a molecular weight of about 100,000 are spirally wound.

As the receptor layer 3 used in the present invention, various receptor layers such as a porous layer system can be used, but it is preferable to use a binder mainly composed of a water-soluble resin or a water-absorbent resin. The water-soluble resin is soluble in water or a mixed solvent of water and alcohol, and conventionally known various resins are used. For example, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl caprolactam, poly (meth) acrylic acid, cellulosic resins (CMC, HEC,
HPC, etc.), water-soluble resins such as polyacrylamide, polyethylene oxide, polyethylene glycol, polyvinyl acetal resin, polyvinyl methyl ether, polyamine, polyethylene imine, casein, gelatin, starch and / or copolymers thereof, cation, anion-modified At least one or more materials are used.

The above-mentioned water-absorbing resin is obtained by crosslinking the above-mentioned water-soluble resin to make it water-absorbing and water-insoluble. The water-absorbing resin is obtained by partially crosslinking the water-soluble resin or grafting the water-soluble resin. Some are coated, and some are crosslinked by a crosslinking agent, heating, or ionizing radiation after coating. Other than these, there are copolymers of a hydrophilic monomer and a hydrophobic monomer, for example, a water-absorbing alkyd resin, a polyester resin, polyvinyl acetate, a vinyl chloride-vinyl acetate copolymer resin,
NBR resin, SBR resin, polyurethane resin, acrylic resin, polyamide, etc. are used alone, as a mixture, or as a modified product. The modified product is, for example, one obtained by copolymerizing or grafting a hydroxyl group, a carboxylic acid, a sulfonic acid, a quaternary ammonium salt-containing monomer or an oligomer, and increasing the hydrophilicity.

The receptor layer of the present invention is preferably formed by applying a composition containing an ionizing radiation-curable hydrophilic monomer and / or oligomer, irradiating the composition with ionizing radiation, and curing the composition. Performance such as abrasion can be further improved. The above hydrophilic monomer and / or oligomer can be used in either monofunctional or polyfunctional form.
Examples of the monofunctional monomer and / or oligomer include epoxy (meth) acrylate, saturated polyester /
Oligomers such as styrene, polyethylene (meth) acrylate, polyether (meth) acrylate, silicon (meth) acrylate, polybutadiene (meth) acrylate, polyene / thiol, polystyrylethyl (meth) acrylate, and polyamide (meth) acrylate; styrene; Vinyl acetate, vinyl monomers such as N-vinylpyrrolidone, N, N-dimethylaminomethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, butyl (meth) ) Acrylate, 2-
Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, hydroxybutyl (meth) acrylate, n-hexyl acrylate, cyclohexyl acrylate, n-decyl acrylate, isobornyl (meth) acrylate, Dicyclopentanyloxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, nonylphenoxyethyl (meth) acrylate, lauryl (meth) acrylate, phenylglycidyl ether (meth) acrylate, acryloylmorpholine And the like.

Examples of the ionizing radiation-curable hydrophilic polyfunctional monomer and / or oligomer include the following. (1) Ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, glycerin tri (meth) acrylate, etc. Representative polyhydric alcohol or polyhydric alcohol condensate and a plurality of condensates of (meth) acrylic acid. (2) N, N'-methylenebis (meth) acrylamide.

(3) Esters of allyl alcohol with polybasic acids represented by diallyl phthalate, diallyl maleate, diallyl terephthalate, triallyl cyanurate, triallyl isocyanurate, triallyl phosphate and the like. (4) By reacting acrylamide or an acrylamide derivative with a (di) aldehyde such as glyoxal in the presence of a catalyst, at least -O-CH (OH) -CH (O
H) -NH-CO-CR = CH ₂ -introduced natural or synthetic water-soluble polymer compound (where R represents a hydrogen atom or an alkyl group).

The natural water-soluble polymer compounds include:
Casein, gelatin, starch-based polysaccharides (dextrin, soluble starch, pregelatinized starch, brilan, etc.) and derivatives thereof and cellulose derivatives (nitrocellulose,
Carboxymethylcellulose (CMC), methylcellulose (MC), hydroxypropylmethylcellulose (HPMC), ethylcellulose (EC), hydroxyethylcellulose (HEC), hydroxypropylcellulose (HPC), etc.]. Examples of the synthetic water-soluble polymer compound include completely saponified or partially saponified polyvinyl alcohol.

(5) Polyvinyl alcohol having at least one functional group selected from a (meth) acryloyl group, a haloalkyl (meth) acryloyl group, and N-methylolacrylamide. (6) trimethylolpropane tri (meth) acrylate, polyethylene oxide-modified trimethylolpropane tri (meth) acrylate, polypropylene oxide-modified trimethylolpropane tri (meth) acrylate,
Glycerol tri (meth) acrylate, polyethylene oxide-modified glycerol tri (meth) acrylate,
Polypropylene oxide modified glycerol tri (meth)
Acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropanetetra (meth)
Acrylate, dipentaerythritol tetra (meth)
Acrylate, dipentaerythritol penta (meth)
Acrylate, dipentaerythritol hexa (meth)
Examples include acrylate, caprolactone-modified hexaacrylate, and polycaprolactone-modified hexaacrylate, but are not limited thereto.

The receiving layer of the recording sheet of the present invention comprises:
Since a hydrophilic polymer other than those described above can be contained, the ink absorption and drying properties are further improved, and the curl of the recording sheet due to curing shrinkage after irradiation with ionizing radiation can be suppressed. The hydrophilic polymer is a polymer having a hydrophilic functional group such as a carboxyl group, a carboxylic acid group, a sulfonic acid group, a sulfonic acid group, a hydroxyl group, an ether group, and an acid amide group. Examples include polyvinyl alcohol, poly (meth) acrylic acid and its salts, cellulose derivatives such as hydroxyethylcellulose and carboxymethylcellulose, gelatin and its derivatives, acrylic acid-vinyl alcohol copolymer, and the like.

The ionizing radiation-curable resin used in the present invention may or may not be cured with an electron beam. However, when it is cured with an ultraviolet ray, a photopolymerization initiator may be used.
A photopolymerization accelerator is used. As the photopolymerization initiator, for example, acetophenone, benzophenone, benzoin ether, chloroacetophenone, diethoxyacetophenone, hydroxyacetophenone, α-aminoacetophenone, benzylmethylketal, thioxanthone, α-
Examples include acyl oxime esters, acyl phosphine oxides, glyoxy esters, 3-ketocoumarin, 2-ethylanthraquinone, camphorquinone, benzyl, Michler's ketone and the like. As photopolymerization accelerators, amine compounds such as N-methyldiethanolamine, triethanolammon, diethanolamine, isoamyl P-dimethylaminobenzoate, N, N-diethyl-P-aminobenzonitrile, and tri-n-butylphosphine Known compounds such as phosphorus compounds and chlorine compounds such as hexachloroethane can be used alone or in combination of two or more. The mixing ratio of these polymerization initiators and accelerators is preferably about 0.1 to 15%, more preferably about 0.5 to 10%, based on the total weight of the composition.

In the receiving layer, the dye fixing property is improved.
Various additives can also be added. In addition, various surface activities
Active agent, antioxidant, UV absorber, defoamer, high hydrophilicity
Mixed with various modified oils as long as the object of the present invention is not hindered.
They can be used in combination. The receiver thus obtained is
The container composition is prepared by various known coating methods, for example,
Gravure coat, gravure reverse coat, roll coat
G, wire bar coat, blade coat, knife coat
G, air knife coat, comma coat, slot die
Coating on substrate sheet by coat, dip coat, etc.
And dried to form the receiving layer. Especially radiation
The radiation-curable resin composition is coated by irradiating ultraviolet rays or electron beams.
Can form a receptor layer by curing
You. The coating amount of the receiving layer is not particularly limited,
If the dry weight is too small, the object of the present invention may not be achieved.
If not, the recording sensitivity of the recording sheet will decrease if the amount is too large.
Dry weight
0.1 to 50 g / m ^Two, Preferably 3 to 30 g /
m^TwoIt is good to apply within the range. 0.1 g / m coating amount
^TwoIf it is less than this, the ink absorption is not sufficient and
And 50g / m^TwoBeyond, economic disadvantages increase
Is not preferred.

As a radiation irradiation device, for example, in the case of an electron beam, the irradiation dose is preferably in the range of 0.1 Mrad to 20 Mrad. If it is less than 0.1 Mrad, curing may be insufficient. Deterioration of the support may be accelerated, resulting in a decrease in sheet strength or discoloration. Acceleration voltage for electron beam irradiation is 100 kV
~ 300 kV is preferred. If it is less than 100 kV, it is difficult to extract an electron beam. If it exceeds 300 kV, the protective wall of the electron beam irradiation device must be considerably thick, and the size of the device increases. In the case of ultraviolet light, an ultraviolet irradiation device having a xenon lamp, a high-pressure mercury lamp, or a metal halide lamp as a light source can be used. The amount of light, the arrangement of the light source, and the like are determined depending on the device used. When a high-pressure mercury lamp is used, the transfer speed is 20 to 60 m / m by a lamp having a light amount of 80 to 120 W / cm.
It is preferable to cure by irradiating 1 to 4 times per minute. Also,
On the surface (rear surface) of the base sheet opposite to the surface on which the receiving layer is formed, a layer having the same composition as the receiving layer, a conventionally known curl preventing layer, antistatic layer, or the like may be provided.

[0027]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. In the text, "part" or "%" means
Unless otherwise specified, it is based on weight. Example 1 A 100 μm-thick transparent polyethylene terephthalate film (Lumirror Q80D manufactured by Toray Industries, Inc., having been subjected to corona discharge treatment) was used as a base sheet. The product 1 was applied by a bar coating method so that the applied amount at the time of drying was 10 g / m ² . After the application, drying was performed at 120 ° C. for 5 minutes to form a receiving layer, and a recording sheet of Example 1 was prepared.

Receiving layer composition 1 100 parts of polyvinylpyrrolidone (K90 manufactured by BASF) 10 parts of protein particles

(Example 2) The following receiving layer composition 21 was applied onto the easily treated surface of the base sheet under the same conditions used in Example 1 by corona discharge so as to have a dry coating amount of 7 g / m ^2. Was applied by a bar coating method. After the application, the coating is dried at 120 ° C. for 5 minutes, and the receiving layer composition 22 is further dried on the receiving layer of the receiving layer composition 21 by a bar coating method so that the coating amount at the time of drying is 3 g / m ^2. Applied. 120 ° C after application
Drying was performed for 5 minutes to form a two-layer receiving layer, and a recording sheet of Example 2 was prepared. Receiving layer composition 21 Urethane resin (HUX290H manufactured by Asahi Denka Kogyo KK) 30 parts (in terms of solid content) 70 parts of protein particles Receiving layer composition 22 Polyvinyl pyrrolidone (K90 manufactured by BASF) 100 parts

(Example 3) The following receiving layer composition 3 was applied to the surface of the base sheet under the same conditions used in Example 1 under the same conditions, which had been subjected to the corona discharge treatment, so that the coating amount upon drying was 10 g / m ^2. Was applied by a bar coating method. After the application, the coating was dried at 120 ° C. for 5 minutes. Thereafter, an electron beam was applied at an irradiation dose of 5 Mrad to form a receiving layer, and a recording sheet of Example 3 was prepared. Receiving layer composition 3 Polyvinyl pyrrolidone (K90 manufactured by BASF) 70 parts Protein particles 10 parts Hydrophilic bifunctional monomer 20 parts (Denacol acrylate DA-701 manufactured by Nagase Kasei Kogyo Co., Ltd.)

(Example 4) The following receiving layer composition 41 was applied to the surface of the substrate sheet used in Example 1 under the same conditions, which had been subjected to corona discharge, so as to have a dry coating amount of 7 g / m ^2. Was applied by a bar coating method. After the application, drying is performed under the conditions of 120 ° C. for 5 minutes, and the receiving layer composition 42 is further dried on the receiving layer of the receiving layer composition 41 by a bar coating method so that the coating amount when dried becomes 3 g / m ^2. Applied. 120 ° C after application
Drying was carried out under the conditions of 5 minutes, and then an electron beam was applied at an irradiation dose of 5 Mrad to form a two-layer receiving layer, and a recording sheet of Example 4 was prepared.

Receiving layer composition 41 Urethane resin (HUX290H manufactured by Asahi Denka Kogyo KK) 30 parts (in terms of solid content) 70 parts of protein particles Receiving layer composition 42 Polyvinyl pyrrolidone (K90 manufactured by BASF) 70 parts Hydrophilic bifunctional 20 parts of monomer (Denacol acrylate DA-701 manufactured by Nagase Kasei Kogyo Co., Ltd.)

(Comparative Example 1) The following receiving layer composition 5 was applied to the easily treated surface of the base sheet under the same conditions used in Example 1 by corona discharge so as to have a dry coating amount of 10 g / m ^2. Was applied by a bar coating method. After the application, drying was performed at 120 ° C. for 5 minutes to form a receiving layer, and a recording sheet of Comparative Example 1 was prepared. Receiving layer composition 5 100 parts of polyvinylpyrrolidone (K90 manufactured by BASF)

Using the ink jet printer (BJC-600J manufactured by CANON), test patterns were printed on the recording sheets of the above Examples and Comparative Examples, and the results shown in Table 1 below were obtained. In addition, the evaluation method of each performance shown in Table 1 is as follows.

(1) Water Absorption For the printed matter on which the test pattern was formed under the above printing conditions, the printed portion was rubbed with a cotton swab held immediately after printing, and the water absorption was visually checked by coloring the cotton swab. evaluated. The evaluation criteria are as follows. ：: When the printed portion was rubbed with the swab held by hand immediately after printing, the swab was not colored at all. ：: When the printed portion was rubbed with a cotton swab held immediately after printing, the cotton swab was hardly colored. X: When the printed portion was rubbed with the swab held by hand immediately after printing, the swab was colored.

(2) Blocking resistance With respect to the printed matter printed under the above conditions, paper was placed on the solid portion of the printed matter immediately after printing, and after 1 minute and 2 minutes after printing, and 800 g was placed on the paper. Was applied for 1 minute, and migration (blocking) of the printing ink onto the paper was visually examined to evaluate the blocking resistance. The evaluation criteria are as follows. A: Even if a load is applied immediately after printing, no transfer of the printing ink to the paper is observed. Good: Immediately after printing, transfer of the printing ink to the paper was observed by applying a load. However, even if a load was applied one minute after printing, the transfer of the printing ink to the paper was not observed. Δ: Transfer of the printing ink to the paper was observed after a load was applied 1 minute after printing, but transfer of the printing ink to the paper was not recognized even after the load was applied 2 minutes after printing. ×: Transfer of the printing ink to the paper was observed after applying a load two minutes after printing.

[0037]

[Table 1]

[0038]

According to the recording sheet of the present invention, a receiving layer is provided on at least one side of a base sheet, and the receiving layer is a single layer or a multi-layer of two or more layers. Since the receiving layer contains protein particles (at least in one layer), it has excellent water absorption, the surface of the receiving layer becomes fine irregularities, and the receiving layer surface and the base film or paper are overlapped even for a short time after printing. Even when combined, there is no blocking or show-through of ink. The receiving layer is preferably formed by applying a composition containing an ionizing radiation-curable hydrophilic monomer and / or oligomer, irradiating the composition with ionizing radiation, and curing the composition. Etc. are more improved,
Since the receiving layer is cured in a short time by irradiation with ionizing radiation, the receiving layer can be easily formed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of a recording sheet of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Recording sheet 2 Base sheet 3 Reception layer

Continued on the front page (72) Inventor Seiji Take, 1-1-1, Ichigaya-Kaga-cho, Shinjuku-ku, Tokyo Inside Dai Nippon Printing Co., Ltd. (72) Inventor Daigo Morizumi 1-1-1-1, Ichigaya-ga-cho, Shinjuku-ku, Tokyo Dai Nippon Printing Co., Ltd. F-term (reference) 2H086 BA01 BA16 BA34

Claims (4)

[Claims] 1. A recording sheet having a receiving layer provided on at least one side of a base sheet, wherein the receiving layer contains protein particles. 2. A recording sheet having a receiving layer provided on at least one side of a base sheet, wherein the receiving layer is a multilayer having two or more layers, and at least one of the multilayers contains protein particles. A recording sheet characterized by the above-mentioned. 3. The method according to claim 1, wherein the receptor layer is formed by applying a composition containing an ionizing radiation-curable hydrophilic monomer and / or oligomer, irradiating the composition with ionizing radiation, and curing the composition. The recording sheet according to claim 1. 4. The receiving layer comprising a plurality of layers, wherein at least one of the receiving layers is coated with a composition containing an ionizing radiation-curable hydrophilic monomer and / or oligomer, and irradiated with ionizing radiation. The recording sheet according to claim 2, wherein the recording sheet is formed by curing.