JP2002036716A - Ink jet recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording material which is excellent in fingerprint resistance, water resistance, ink absorbency, and transparency, and has enough permeability in using even in a backlight system to look at image by transmitted light from an opposite face of a printing face. SOLUTION: A contact angle of the surface of an ink jet recording material prepared by providing an ink reception layer on a light permeable support with water is 13-35 degrees, and a contact angle with a flaxseed oil is 8-20 degrees. Preferably, the ink reception layer contains a surface active agent having an HLB value of 3-8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink-jet recording material using a light-transmitting support, and particularly for medical use, has good fingerprint resistance, excellent ink absorption, transparency and water resistance, and has a printing surface. The present invention relates to an ink jet recording material having a sufficient transparency even when used in a backlight system in which an image is viewed by light transmitted from the opposite side.

[0002]

2. Description of the Related Art As a recording material used in an ink jet recording system, an ink receiving layer of a hydrophilic polymer, a pigment such as amorphous silica, and a water-soluble binder are provided on a support called ordinary paper or ink jet recording paper. A recording material provided with a porous ink receiving layer made of

For example, Japanese Patent Application Laid-Open Nos. 56-080489, 59-174381, 60-220750, and 6
Nos. 1-332788 and 63-160875;
As disclosed in JP-A-69388 and the like, a recording material in which a support is coated with a hydrophilic polymer such as starch or polyvinyl alcohol has been proposed.

[0004] For example, JP-A-55-51583,
Nos. 6-157, 57-107879, 57-10
No. 7880, No. 59-230787, No. 62-160
No. 277, No. 62-184879, No. 62-1833
Nos. 82 and 64-11877, JP-A-3-215
08, 4-67986, etc., a recording material obtained by applying a silicon-containing pigment such as silica or an alumina sol to a paper support together with an aqueous binder has been proposed.

[0005] Also, Japanese Patent Publication No. 3-56552,
No. 188287, No. 8-132728, No. 10
No. 81064, No. 10-119423, No. 10
No. 175365, No. 10-203006, No. 10-
No. 217601, No. 11-20300, No. 11-
Nos. 20306 and 11-34481 disclose a recording material using fine particles of silica synthesized by a gas phase method (hereinafter referred to as gas phase silica).

On the other hand, it has been studied to produce a transparent recording sheet for OHP or the like or a medical film by an ink jet recording method. For these recording sheets, ink absorbency and transparency are important, but for OHP and medical use,
In addition, characteristics of fingerprint resistance and glare due to return light are important. That is, there is a problem in that it is difficult to see due to fingerprints and glare at the time of handling. In particular, the fingerprint resistance is not particularly noticeable in the case of an opaque support, but is a characteristic that is remarkably exhibited in the case of a light-transmitting support.

JP-A-7-276789 discloses that a transparent support is provided with a colorant receiving layer in which the weight ratio of silica fine particles having an average primary particle size of 10 nm or less to a water-soluble resin is 1.5: 1 to 10: 1. The provided recording material having high ink absorbency and high transparency is disclosed. However, there is no description about improvement of fingerprint resistance and glare.

Japanese Unexamined Patent Publication (Kokai) No. 61-237682 proposes improving the fingerprint resistance by attaching a hydrophobic substance to the surface, but has a drawback that the printability is reduced. JP-A-10-
No. 157286 proposes to improve water resistance and fingerprint resistance by using polyvinyl alcohol and an acrylic emulsion having a saponification degree of 78 to 92 mol% and a polymerization degree of 1700 or more. In order to obtain the ink, reduction in ink absorbency and ink bleeding were inevitable.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet recording material having good anti-fingerprint property, and furthermore, it has less glare, and has good ink absorption and transparency. It is to provide.

[0010]

Means for Solving the Problems The present inventors have conducted sincere studies to solve the above problems, and as a result, have found that the hydrophilicity and lipophilicity of the recording material surface affect the fingerprint resistance, and completed the present invention. I let it.

(1) In an ink jet recording material provided with an ink receiving layer on a light-transmitting support, the surface of the recording material has a contact angle of 13 to 35 degrees with water and a contact angle of 8 to 20 with linseed oil. An ink jet recording material, characterized in that it has a degree.

(2) In an ink jet recording material having an ink receiving layer provided on a light-transmitting support, the ink receiving layer contains a hydrophilic polymer and a surfactant having an HLB value of 3 to 8. 2. The ink jet recording material according to the above item 1, wherein

(3) In an ink jet recording material having an ink receiving layer provided on a light-transmitting support, the ink receiving layer has an inorganic fine particle having an average primary particle diameter of 5 to 50 nm, a hydrophilic polymer, and an HLB value. 3. The ink jet recording material as described in 1 above, comprising 3 to 8 surfactants.

(4) The ink jet recording material as described in (3) above, wherein the inorganic fine particles are fumed silica.

(5) The ink jet recording material as described in any one of (1) to (4) above, wherein a contact angle of the ink receiving layer with linseed oil is 8 to 15 degrees.

(6) The ink receiving layer has an average particle size of 0.5
6. The ink jet recording material according to any one of the items 1 to 5, further comprising an inorganic pigment having a particle size of not less than μm.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
Examples of the light-transmitting support used in the present invention include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate, cellulose ester resins such as diacetate resin, triacetate resin, nitrocellulose and cellulose acetate, and polyolefin resins. , Acrylic resin, polycarbonate resin,
Examples include plastic resin films such as polyvinyl chloride, polyimide resin, polysulfone, polyphenylene oxide, cellophane, and celluloid. Particularly, a polyester film is preferably used because of its properties such as heat resistance and price. The thickness of these resin film supports is preferably about 50 to 250 μm from the viewpoint of curling properties and ease of handling.

In the present invention, the ink-receiving layer coated on the light-transmitting support has a hydrophilic polymer, preferably H
An LB value containing a surfactant having a value of 3 to 8, and an inorganic pigment,
When containing a cationic polymer, a hardening agent, etc. (hereinafter referred to as “swellable ink receiving layer”), a hydrophilic polymer,
Inorganic fine particles, preferably primary particles having an average particle size of 5 to 50
In some cases, the composition contains inorganic fine particles having a particle diameter of 3 nm and a surfactant having an HLB value of 3 to 8 and appropriately contains an inorganic pigment, a crosslinking agent, a cationic polymer, and the like (hereinafter, referred to as a “porous ink receiving layer”). The coating liquid for the ink receiving layer is applied so that a coating layer having a thickness of several tens to several hundreds μm is formed on the support, and then dried. One preferred example of the production method is
The ink receiving layer applied to the light-transmitting support is
It is cooled in the following atmosphere and then dried in a drying step.

In comparison between a general swellable ink-receiving layer and a porous ink-receiving layer, the former has a high gloss, but the surface tends to be glaring, and has poor ink absorbency and poor fingerprint resistance. I have. In particular, when used for medical purposes, ink absorbency is an important characteristic because an image printed by ink jet must sufficiently reproduce the real thing.
In addition, fingerprint resistance is also an important issue when evaluating and judging from an image, and in an OHP application, a projected image becomes unsightly due to fingerprint stains. The increase in the glaring feeling of the surface due to the return light of the external light is not preferable because it becomes difficult to see when using a backlight system in which light is irradiated from the opposite surface to the printing surface and an image is observed from the printing surface. As described above, the porous ink-receiving layer is more preferable for medical use and the like used in the backlight system, but is not yet at a practically sufficient level.

In the present invention, the hydrophilic polymer used in the case of the swellable ink receiving layer is gelatin, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl pyridinium halide, polyacrylamide, sodium polyacrylate, starch, carboxy starch, cationic starch, Examples thereof include dialdehyde starch, casein, ethyl cellulose, carboxymethyl cellulose, polyethylene glycol, polypropylene glycol, styrene-maleic anhydride copolymer, and modified products thereof.

In the present invention, the inorganic fine particles used in the case of the porous ink receiving layer include light calcium carbonate, heavy calcium carbonate, magnesium carbonate, kaolin, titanium dioxide, zinc oxide, zinc hydroxide, calcium silicate, and silicate. Examples include magnesium, synthetic silica, alumina, hydrated alumina hydrate, aluminum oxide, and magnesium hydroxide. Preferably the primary particles have an average particle size of 5 to 5.
Inorganic fine particles of 50 nm are used, and synthetic silica, alumina, and alumina hydrate are selected in view of high printing density, clear image, and low production cost. Particularly, for medical use, the reproducibility of a printed image is required, so that the average particle size of the inorganic fine particles used is preferably small.

Synthetic silica includes those obtained by a wet method and those obtained by a gas phase method. Usually, silica fine particles often refer to wet process silica. As wet silica, silica sol obtained by metathesis of sodium silicate with an acid or the like through an ion exchange resin layer, or colloidal silica obtained by heating and aging this silica sol, gelling silica sol, and changing the production conditions Silica such as those obtained by heating and producing silica gel in which primary particles of several μm to 10 μm are three-dimensional secondary particles having siloxane bonds, and further, silica sol, sodium silicate, sodium aluminate, etc. There are synthetic silicate compounds and the like as main components.

The fumed silica is also called a dry method with respect to a wet method, and is generally produced by a flame hydrolysis method. Specifically, a method of making silicon tetrachloride by burning it with hydrogen and oxygen is generally known, but instead of silicon tetrachloride, silanes such as methyltrichlorosilane and trichlorosilane may be used alone or in a silicon tetrachloride. And can be used in a mixed state. The fumed silica is Aerosil from Nippon Aerosil Co., Ltd. and QS from Tokuyama Co., Ltd.
It is commercially available as a type and can be obtained.

In the present invention, fumed silica is preferably used in view of print density, transparency, gloss, and fingerprint resistance.
From the viewpoint of transparency and gloss, the average primary particle size is 3 to 30 n.
m. However, there is a tendency that glare on the surface is easily caused by external light.

The average particle size of the primary particles of the inorganic fine particles of the present invention is equal to the projected area of each of 100 particles existing within a certain area by observing particles dispersed to such an extent that the primary particles can be distinguished. The average particle size was determined using the diameter of the circle as the particle size of the particles. Similarly, secondary particles were obtained by observing particles dispersed with a gentle shearing force using an electron microscope.

In the present invention, the solid content per unit area of the ink receiving layer is generally 10 g / m ² or more.
A range from 3 to 35 g / m ² is preferred.

The porous ink receiving layer of the present invention has a binder for maintaining the properties as a film. As the binder, a hydrophilic polymer which has high transparency and high penetrability of the ink is preferably used. In using the hydrophilic polymer, it is important that the hydrophilic polymer does not swell during the initial penetration of the ink and does not block the voids. From this viewpoint, the hydrophilic polymer is exemplified as the hydrophilic polymer used in the swellable ink receiving layer. Among the types and the like, a hydrophilic polymer having a low swelling property at around room temperature is preferably used. Particularly preferred hydrophilic polymers are fully or partially saponified polyvinyl alcohols or cationically modified polyvinyl alcohols.

Particularly preferred among polyvinyl alcohols are those partially or completely saponified with a degree of saponification of 80% or more. Polyvinyl alcohol having an average degree of polymerization of 1,000 to 5,000 is preferred.

Further, as the cation-modified polyvinyl alcohol, for example, as described in JP-A-61-10483, a primary to primary amino group or a quaternary ammonium group is added to the main chain or side chain of polyvinyl alcohol. It is a polyvinyl alcohol contained therein.

Further, other hydrophilic polymers can be used in combination, but 20% by weight based on polyvinyl alcohol.
It is preferable that it is not more than about.

In the present invention, the weight ratio of the hydrophilic polymer to the inorganic fine particles in the porous ink receiving layer is determined mainly by the transparency, ink absorbency and surface strength of the ink receiving layer. 60 to 100/8,
Preferably it is in the range of 100/50 to 100/15.
When the ratio of the inorganic fine particles to the hydrophilic polymer is increased, the ink absorbency is improved, but the transparency is reduced, cracks are liable to occur during drying, the surface strength is reduced, and powder is easily dropped. Conversely, when the ratio is reduced, transparency and surface strength are improved, but ink absorbency is reduced.

The surfactant used in the present invention includes cationic surfactants such as aliphatic amine salts, aliphatic quaternary ammonium salts, benzalkonium salts, benzethonium chloride, pyridinium salts, imidazolinium salts and the like. Examples of the amphoteric surfactant include carboxy betaine type, aminocarboxylate, imidazolinium betaine, and lecithin. Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, and polyoxyethylene sorbitan. Fatty acid esters,
One or more kinds are appropriately selected from polyethylene glycol fatty acid esters, sucrose fatty acid esters, fatty acid alkanolamides and the like. Anionic surfactants such as carboxylate and sulfonate can be used, but the amount is limited due to the cohesion with the ink receiving layer composition. Among them, HLB value of 3 to 8 is particularly necessary for adjusting the contact angle with linseed oil.
Are preferably selected.

In the present invention, the contact angle of the surface of the ink jet recording material with water is 13 to 35 degrees, and the contact angle with linseed oil is 8 to 20 degrees. It was found that the fingerprint resistance was good only when the contact angles of water and oil were within the respective ranges. Although the reason is not clear, the fingertip mainly contains moisture from the sweat glands and the oil and fat of the finger, and it is expected that fingerprints will be generated due to these delicate effects.
The ink absorption of the ink receiving layer is roughly determined by the type and amount ratio of the hydrophilic polymer and the inorganic fine particles, and when the contact angle with water or linseed oil is not within the target range, a surfactant,
It is preferable to adjust with an oil droplet and an organic solvent. Particularly, a surfactant having an HLB value of 3 to 8, which is effective with a small amount of addition,
This is preferable because the influence on ink jet suitability such as ink absorbency is small. By using a hydrophilic polymer and a hydrophobic polymer such as styrene-butadiene-based or urethane-based latex in combination with water, and the contact angle with linseed oil can be within the scope of the present invention, but the ink absorption The drop is large. In particular, in the case of the swellable ink receiving layer, when the content of the hydrophobic polymer is in the range of 10 to 50% by weight of the ink receiving layer, ink absorption and fingerprint resistance can be used. In the case of the porous ink receiving layer, the amount ratio of the hydrophobic polymer to the hydrophilic polymer is approximately in the range of 1/10 to 1/1,
When the weight ratio of the total of the hydrophilic polymer and the hydrophobic polymer to the inorganic fine particles is in the range of 1/10 to 3/10, the ink absorption and the fingerprint resistance fall within the usable range.

If the contact angle of the recording material surface with water is greater than 35 degrees, the moisture in the fingerprint remains on the surface, causing stains, and has low water-based ink permeability, so that feathering is likely to occur. If the angle is smaller than 13 degrees, the surface is easily deformed due to the penetration of moisture in the fingerprint, and the spread of the water-based ink becomes large, which is not preferable. Preferably 13
~ 30 degrees.

If the contact angle with linseed oil is larger than 20 degrees, the oils and fats in the fingerprint are likely to remain on the surface and stains are conspicuous, and if it is smaller than 8 degrees, the permeability of the aqueous ink is inferior. Preferably it is 8 to 15 degrees.

In the present invention, various oil droplets can be contained to adjust the contact angle of the recording material surface with water and linseed oil. Such oil droplets include hydrophobic high-boiling organic solvents having a solubility in water at room temperature of 0.01% by weight or less (for example, liquid paraffin, dioctyl phthalate,
Tricresyl phosphate, silicon oil, etc.) and polymer particles (for example, particles obtained by polymerizing one or more polymerizable monomers such as styrene, butyl acrylate, divinylbenzene, butyl methacrylate, and hydroxyethyl methacrylate). Such oil droplets are preferably 5 to 50% by weight with respect to the hydrophilic binder
Can be used.

In the present invention, a protective layer may be provided on the ink receiving layer as long as the ink absorbency and transparency are not significantly reduced, but the contact angle of the protective layer surface with water and linseed oil is not limited by the present invention. Must be within the range. The thickness of a general protective layer is 5 μm or less.

The ink-jet recording material of the present invention is prepared by using JI
The haze value specified in SK-7105 is preferably 25% or less, more preferably 18% or less. When the numerical value is high, especially when used in a medical backlight system, the sharpness of an image is reduced, and it is easy to make a mistake in viewing.

The glare, which is particularly problematic in medical applications, is caused by the reflection of external light from the surface of the recording material. Even when the gloss is evaluated at a gloss value of 60 or 75 degrees, a sufficient correlation with the glare is obtained. However, it was found that the relationship between the image clarity C value obtained by the measurement of the image clarity and the feeling of glare caused by the reflected light, which is reflected light, was deep.

The image clarity of the present invention is an index of how clear the image is when the object is captured on the coating film surface, and is defined in JIS-H-8686. In the present invention, an image clarity measuring device manufactured by Suga Test Instruments Co., Ltd. is used, and evaluation is performed based on image clarity C value obtained using an optical comb width of 2.0 mm. The larger the image clarity C value, the better the surface property, which is preferable for general photography, printing, and publishing applications. However, in the case of an ink-jet recording material for backlit using a light-transmitting support, the surface of the recording material It was found that when the image clarity was high, the image due to the transmitted light was glaring due to the light reflection by the external light, making it difficult to see. In particular, when it is necessary to make a serious judgment from the image content, such as in a medical application, it is particularly important to improve the glare. In the present invention, the image clarity C value is generally 85% or less, preferably 83% or less, more preferably 80% or less.

In the present invention, an inorganic pigment having an average particle size of preferably 0.5 μm or more is preferably used for reducing glare of the surface particularly for medical use. For example, light calcium carbonate,
Heavy calcium carbonate, magnesium carbonate, kaolin, titanium dioxide, zinc oxide, zinc hydroxide, calcium silicate,
Examples include magnesium silicate, synthetic silica, alumina, hydrated alumina hydrate, aluminum oxide, and magnesium hydroxide. Synthetic silica, particularly wet-process silica, is preferably selected from the viewpoint of reducing the ink absorbency and the glare of the surface. If the average particle size is smaller than 0.5 μm, the effect of reducing the return light due to light reflection cannot be obtained. Preferably, the average particle size is larger than 1 μm from the viewpoint of improving the glittering feeling. The content of the inorganic pigment having an average particle size of 0.5 μm or more is about 0.1 to 5 g / m ^{2 in the} unit area of the recording material. Preferably, the content is 0.1 to ² g / m ² . 0.
If it is less than 1 g / m ² , the effect of improving the feeling of glare is small,
If it is more than 5 g / m ² , transparency will decrease.

The ink receiving layer of the present invention preferably contains a cationic compound. Examples of the cationic compound used in the present invention include a cationic polymer and a water-soluble metal compound used for the purpose of improving water resistance. When the cationic polymer is used in combination with fumed silica, the transparency tends to decrease. However, the water-soluble metal compound suppresses the generation of fine cracks and conversely improves the transparency. Therefore, in the present invention, the ink absorption is good and water-resistant due to the fumed silica and the water-soluble metal compound,
There is an advantage that transparency is increased.

The cationic polymer used in the present invention includes polyethyleneimine, polydiallylamine, polyallylamine, JP-A-59-20696 and JP-A-59-20696.
No. 33176, No. 59-33177, No. 59-155
Nos. 088, 60-11389, 60-49990
No. 60-83882, No. 60-109894,
Nos. 62-198493, 63-49478, 6
3-115780, 63-280681, JP-A-1-40371, 6-234268, 7-12
Polymers having primary to tertiary amino groups and quaternary ammonium groups described in JP-A Nos. 5411 and 10-193776 are preferably used. The molecular weight of these cationic polymers is 5,000 or more, and more preferably 5,000 to 10
About 10,000 is preferable.

The use amount of these cationic polymers is 1 to 10% by weight, preferably 2 to 7% by weight, based on the inorganic fine particles.

The water-soluble metal compound used in the present invention includes, for example, water-soluble polyvalent metal salts. Water-soluble salts of metals selected from calcium, barium, manganese, copper, cobalt, nickel, aluminum, iron, zinc, zirconium, chromium, magnesium, tungsten, and molybdenum. Specifically, for example, calcium acetate, calcium chloride, calcium formate, calcium sulfate, barium acetate, barium sulfate, barium phosphate, manganese chloride, manganese acetate, manganese formate dihydrate, manganese ammonium sulfate hexahydrate, chlorinated chloride Cupric, ammonium copper (II) chloride dihydrate, copper sulfate, cobalt chloride,
Cobalt thiocyanate, cobalt sulfate, nickel sulfate hexahydrate, nickel chloride hexahydrate, nickel acetate tetrahydrate, nickel ammonium sulfate hexahydrate, nickel amidosulfate tetrahydrate, aluminum sulfate, aluminum sulfite, Aluminum thiosulfate, poly aluminum chloride, aluminum nitrate nonahydrate, aluminum chloride hexahydrate,
Ferrous bromide, ferrous chloride, ferric chloride, ferrous sulfate, ferric sulfate, zinc bromide, zinc chloride, zinc nitrate hexahydrate, zinc sulfate, zirconium acetate, zirconium chloride, chloride Zirconium oxide octahydrate, zirconium hydroxychloride, chromium acetate, chromium sulfate, magnesium sulfate, magnesium chloride hexahydrate, magnesium citrate nonahydrate, sodium phosphotungstate, sodium tungsten citrate, 12 tungstophosphate n Hydrate, 12-tungstosilicic acid 26-hydrate, molybdenum chloride, 12-molybdophosphate n-hydrate and the like. A zirconium-based compound is preferable in terms of characteristics.

As the cationic compound, inorganic compounds
Basic polyhydroxyl is an aluminum-containing cationic polymer
Aluminum oxide compounds. Basic polyhydroxylation
The aluminum compound has a main component represented by the following general formulas 1 and 2
Or 3, for example, [Al₆(OH)_Fifteen]³⁺, [A
l₈(OH)₂₀]⁴⁺, [Al₁₃(OH)₃₄]⁵⁺, [Al
_{twenty one}(OH)₆₀]³⁺Polynuclear condensation of basic macromolecules such as,
Water-soluble polyaluminum hydroxide with stable ion content
Nium.

[Al ₂ (OH) _n Cl _6-n ] _m Formula 1 [Al (OH) ₃ ] _n AlCl ₃ Formula 2 Al _n (OH) _m Cl _(3n-m) 0 <m < 3n ・ ・ Equation 3

These are water treatment agents under the name of polyaluminum chloride (PAC) from Taki Chemical Co., Ltd., and polyaluminum hydroxide (Paho) from Asada Chemical Co., Ltd. It is marketed by RIKEN GREEN under the name Purachem WT and from other manufacturers for the same purpose, and various grades are readily available. In the present invention, these commercial products can be used as they are,
Some substances have an inappropriately low pH, and in such a case, the pH can be appropriately adjusted and used.

In the present invention, the content of the water-soluble metal compound in the ink receiving layer is 0.1 g / m ^{2 to} 10 g / m ² .
m ^2, preferably from ^{0.2g / m 2 ~5g / m 2} .

Two or more of the above-mentioned cationic compounds can be used in combination. For example, a cationic polymer and a water-soluble metal compound may be used in combination.

In the present invention, the ink receiving layer can be hardened with an appropriate hardener for the purpose of improving water resistance and dot reproducibility. Specific examples of the hardener include aldehyde compounds such as formaldehyde and glutaraldehyde, ketone compounds such as diacetyl and chloropentanedione, and bis (2-chloroethylurea) -2-hydroxy-4,6-dichloro-1. 3,3,5 triazine, a compound having a reactive halogen as described in U.S. Pat. No. 3,288,775, divinyl sulfone, a compound having a reactive olefin as described in U.S. Pat. No. 3,635,718, U.S. Pat. N-methylol compounds as described in Japanese Patent No. 2,732,316, U.S. Pat. No. 3,103,43
No. 7, isocyanates described in US Pat.
Aziridine compounds as described in US Pat. Nos. 7,280 and 2,983,611; carbodiimide-based compounds as described in US Pat. No. 3,100,704; US Pat.
No. 1,537, epoxy compounds, halogen carboxaldehydes such as mucochloric acid, dioxane derivatives such as dihydroxydioxane, and inorganic hardeners such as chrome alum, zirconium sulfate, boric acid and borate. They can be used alone or in combination of two or more. The addition amount of the hardener is 0.01 to 40 with respect to 100 g of the hydrophilic polymer constituting the ink receiving layer.
g is preferable, and 0.1 to 30 g is more preferable.

In the present invention, the ink receiving layer further contains a coloring dye, a coloring pigment, a fixing agent for the ink dye, an ultraviolet absorber, an antioxidant, a dispersant for the pigment, an antifoaming agent, an organic solvent, a leveling agent, Preservatives, optical brighteners, viscosity stabilizers,
Various known additives such as a pH adjuster can also be added.

In the present invention, the coating method is not particularly limited, and a known coating method can be used. For example, there are a slide bead method, a curtain method, an extrusion method, an air knife method, a roll coating method, a ked bar coating method, and the like.

In the present invention, the ink receiving layer may be composed of one layer or a plurality of layers. In the case of a plurality of layers, the layers may be divided according to functions, but the uppermost layer needs to be within the scope of the present invention. Although a protective layer having ink permeability may be provided on the surface of the ink receiving layer, it is necessary that the properties of the protective layer surface be within the range of the present invention. 2
When more than one ink receiving layer is applied simultaneously, it means the total solid content ratio of all layers and the total applied amount.

In order to adjust the transparency and color tone of the light-transmitting support, for example, inorganic fine particles are mixed with a thermoplastic resin. The inorganic fine particles include calcium carbonate, titanium dioxide, talc, silica and the like. And coloring pigments such as carbon black. In the present invention, preferably, the opacity of the support is 60% or less. If it is larger than 60%, the light transmittance is poor and an unclear dark image is obtained. 5
%, The transmitted light becomes strong and the image becomes difficult to see depending on the illumination of the light source. Particularly for medical use, a blue PET film colored blue is preferably used.

When the coating liquid for the ink receiving layer is applied to the plastic resin film support, a corona discharge treatment, a flame treatment, an ultraviolet irradiation treatment, a plasma treatment and the like are usually performed prior to the application.

In the present invention, it is preferable to provide a primer layer mainly composed of a synthetic resin on a light-transmitting support such as a plastic resin film. After applying the coating liquid for the ink receiving layer on the primer layer, the coating liquid is cooled and dried at a relatively low temperature, whereby the transparency is further improved.

The primer layer provided on the film mainly comprises a synthetic resin. Examples of such a synthetic resin include acrylic resin, polyester resin, vinylidene chloride, vinyl chloride resin, vinyl acetate resin, polystyrene, polyamide resin, and polyurethane resin. Among these, acrylic resin, polyester resin, vinylidene chloride resin, and polyurethane resin are particularly preferable. As the acrylic resin, a homopolymer of an alkyl acrylate and an alkyl methacrylate or a copolymer thereof is generally used. As the polyester resin, a polycondensate of a glycol (eg, ethylene glycol, diethylene glycol) and a polybasic acid such as an aliphatic or aromatic dibasic acid is generally used. As the vinylidene chloride resin, a homopolymer or a copolymer with an alkyl acrylate, an alkyl methacrylate and / or acrylonitrile is preferable. As the polyurethane resin, an aqueous dispersion type polyurethane emulsion is preferable. These resins can be coated on a support as a solution or an aqueous solution of an organic solvent, but are preferably water-dispersible polymers, and are coated on the support as an emulsion or latex.

These synthetic resins contain at least 60% by weight based on the total solid content of the primer layer.
Preferably, the content is 80% by weight or more. Furthermore, a surfactant, an isocyanate,
It may contain a crosslinking agent such as epoxy, fine particles such as colloidal silica, and a water-soluble polymer such as gelatin and polyvinyl alcohol.

The primer layer is formed on a support by 0.01
It is provided with a film thickness (dry film thickness) of ５5 μm. Preferably, it is in the range of 0.05 to 5 μm.

The support in the present invention may be coated with various back coat layers for antistatic properties, transport properties, curling prevention properties, and the like. The back coat layer can contain an inorganic antistatic agent, an organic antistatic agent, a hydrophilic binder, a latex, a curing agent, a surfactant and the like in an appropriate combination.

[0062]

EXAMPLES The present invention will be described below in detail with reference to examples, but the contents of the present invention are not limited to the examples.

Examples 1 and 2 The following light-transmitting supports were prepared. <Support A> Polyethylene terephthalate film having a thickness of 170 μm and containing a blue inorganic pigment (opacity 15%)
Surface treated with oxygen plasma. <Support B> Polyethylene terephthalate film having a thickness of 170 μm and containing a blue inorganic pigment (opacity 15%)
A primer layer having the following composition was provided thereon such that the dry film thickness was 0.3 μm. Primer layer: latex (weight average molecular weight 42,000) of vinylidene chloride: methyl acrylate: acrylic acid (90: 9: 1, wt%).

A coating solution of the ink receiving layer having the following composition was applied to the above two types of supports by a slide bead coating device and dried. The ink receiving layer coating solution shown below was prepared so as to have a solid content of 10% by weight, and the solid content was 20 g / g.
It was coated so as to be in m ^2. The material using the support A was used as the ink jet recording material of Example 1, and the material using the support B was used as the ink jet recording material of Example 2.

<Ink receiving layer coating liquid> 95 parts of fumed silica (average primary particle diameter 7 nm, average secondary particle diameter 0.21 μm) Wet method silica 5 parts (Nipsil E-220A, manufactured by Nippon Silica Co., average particle diameter) Diameter 2 μm) Dimethyl diallyl ammonium chloride homopolymer 3 parts Boric acid 4 parts Polyvinyl alcohol 20 parts (Saponification degree 88%, average polymerization degree 3500) Surfactant (SO-10 manufactured by Nikko Chemicals; HLB value 4.3) 0 parts Zirconium acetate 2 parts

The drying conditions after coating are shown below. 3 at 5 ° C
After cooling for 0 seconds, the total solid content was reduced to 90% by weight at 45 ° C.
Dried at 10% RH and then at 35 ° C. 10% RH.

The following evaluation was performed on the ink jet recording material prepared as described above. Table 1 shows the results.
Shown in

<Contact Angle> A drop of water and linseed oil (approximately 0.1 m) was placed on the surface of the sample under the environmental conditions of 23 ° C. and 55% RH.
The contact angle immediately after dropping l) was measured from the recorded image.

<Image clarity> The image clarity C value specified by JIS-H-8686 was measured with an optical comb width of 2.0 mm using a Suga Test Machine Co., Ltd. The sample is fixed to the sample mounting table by a suction method so that the measured value does not decrease due to curl or the like. Each sample was measured five times, and the average value was adopted. When the image clarity C value is larger than 85%, the glaring feeling visually becomes large. Preferably it is 83% or less.

<Fingerprint Resistance> After pressing a finger against the ink receiving layer, the surface was observed and evaluated according to the following criteria. ：: Fingerprint is not recognized. Δ: Fingerprint is slightly recognized. ×: Fingerprint is clearly recognized.

<Ink Absorption> Using a plotter (Novajet-PRO42e manufactured by ENCAD) and GS ink, C, M, and Y were printed at 100% each, and immediately after printing, PPC paper was overlaid on the printing section. The ink was lightly pressed and the amount of the ink transferred to the PPC paper was visually observed and evaluated according to the following criteria. ：: No transfer at all. Δ: Transfer is available but can be used. ×: Transfer is large and cannot be used.

<Haze Value of Ink Receiving Layer> The haze value defined by JIS-K-7105 of the polyethylene terephthalate film support to be used and the obtained ink jet recording material was determined by using a Poic integrating sphere haze meter (Nihon Seimitsu Kogaku Co., Ltd.) )) And calculated from the difference.

Example 3 An ink jet recording material of Example 3 was obtained in the same manner as in Example 2 except that the composition of the ink receiving layer was changed as follows. Table 1 shows the evaluation results.

<Ink receiving layer coating liquid> 95 parts of fumed silica (average primary particle diameter 7 nm, average secondary particle diameter 0.21 μm) Wet method silica 5 parts (Nipsil E-220A, manufactured by Nippon Silica Co., average particle diameter) Diameter 2 μm) Dimethyldiallylammonium chloride homopolymer 3 parts Boric acid 4 parts Polyvinyl alcohol 20 parts (Saponification degree 88%, average polymerization degree 3500) Surfactant (BO-2, Nikko Chemicals Co .; HLB value 7.5) 1. 5 parts Zirconium acetate 2 parts

Example 4 An ink jet recording material of Example 4 was obtained in the same manner as in Example 2 except that the composition of the ink receiving layer was changed as described below. The evaluation results are shown in Table 1.

<Coating liquid for ink receiving layer> 100 parts of fumed silica (average primary particle diameter 7 nm, average secondary particle diameter 0.21 μm) Dimethyl diallyl ammonium chloride homopolymer 3 parts Boric acid 4 parts Polyvinyl alcohol 20 parts (Saponification) Degree 88%, average degree of polymerization 3500) Surfactant (SO-10 manufactured by Nikko Chemicals; HLB value 4.3) 1.0 part 2 parts zirconium acetate

Example 5 An ink jet recording material of Example 5 was obtained in the same manner as in Example 2 except that the composition of the ink receiving layer was changed as follows. Table 1 shows the evaluation results.

<Ink receiving layer coating liquid> Gelatin 50 parts Polyvinyl pyrrolidone 45 parts Wet method silica 5 parts (Nippon Silica Co., Ltd., Nip Seal E-220A, average particle size 2 μm) Surfactant (Nikko Chemicals SO-10; HLB value 4.3) 5.5 parts

Example 6 An ink jet recording material of Example 6 was obtained in the same manner as in Example 1 except that zirconium acetate was omitted in the composition of the ink receiving layer of Example 1. Table 1 shows the evaluation results.

Example 7 An ink jet recording material of Example 7 was obtained in the same manner as in Example 2 except that 10 parts of a high boiling point organic solvent (dioctyl phthalate) was used instead of the surfactant in the composition of the ink receiving layer. . Table 1 shows the evaluation results.

Example 8 An ink jet recording material of Example 8 was obtained in the same manner as in Example 2 except that the composition of the ink receiving layer was changed as follows. Table 1 shows the evaluation results.

<Ink receiving layer coating liquid> 95 parts of fumed silica (average primary particle diameter 7 nm, average secondary particle diameter 0.21 μm) Wet method silica 5 parts (Nipsil E-220A, manufactured by Nippon Silica Co., average particle diameter) Diameter 2 μm) Dimethyl diallyl ammonium chloride homopolymer 3 parts Boric acid 4 parts Polyvinyl alcohol 20 parts (Saponification degree 88%, average polymerization degree 3500) Surfactant (BO-7; HLB value 10.5, Nikko Chemicals Co., Ltd.) 3 parts 2 parts of zirconium acetate

Example 9 An ink jet recording material of Example 9 was obtained in the same manner as in Example 2 except that the composition of the ink receiving layer was changed as follows. Table 1 shows the evaluation results.

<Ink receiving layer coating liquid> 95 parts of fumed silica (average primary particle diameter 7 nm, average secondary particle diameter 0.21 μm) Wet method silica 5 parts (Nipsil E-220A, manufactured by Nippon Silica Co., average particle diameter) Diameter 2 μm) Boric acid 4 parts Polyvinyl alcohol 10 parts (Saponification degree 88%, average polymerization degree 3500) Styrene / butadiene latex 5 parts (Nippon Synthetic Rubber Co., Ltd., ISR-0850)

Comparative Example 1 An ink jet recording material of Comparative Example 1 was obtained in the same manner as in Example 1 except that the surfactant contained in the ink receiving layer was omitted. Table 1 shows the evaluation results.

Comparative Example 2 An ink jet recording material of Comparative Example 2 was obtained in the same manner as in Example 5, except that the surfactant contained in the ink receiving layer was omitted. Table 1 shows the evaluation results.

Comparative Example 3 An ink jet recording material of Comparative Example 3 was obtained in the same manner as in Example 5, except that the composition of the ink receiving layer was changed as follows. Table 1 shows the evaluation results.

<Ink receiving layer coating liquid> 100 parts of polyvinyl alcohol (degree of saponification: 85%, average polymerization degree: 3500) 100 parts of acrylic emulsion (oil-in-water emulsion) 100 parts of plasticizer (dioctyl phthalate) 10 parts

[0089]

[Table 1] 角 Contact angle (degree) Fingerprint resistance Image clarity ( %) Ink absorbency Haze ゛ value (%) Water Linseed oil ─────────────────────────────────── Example 1 18 10 ○ 75 ○ 8.6 Example 2 17 9 ○ 74 ○ 7.5 Example 3 16 8 ○ 72 ○ 8.9 Example 4 19 11 ○ 86 ○ 7.4 Example 5 35 20 △ 82 △ 7.1 Example 6 20 10 ○ 76 ○ 9.5 Example 7 30 16 △ 78 △ 12.2 Example 8 33 19 △ 76 ○ 9.8 Example 9 29 18 △ 80 △ 13.1 ─── ──────────────────────────────── Comparative Example 1 21 23 × 75 ○ 8.5 Comparative Example 2 36 32 × 83 △ 7.0 Comparative Example 3 29 36 × 86 △ 6.8 ───────────── ─────────────────────

Results: In Example 2, the primer layer was provided on the polyethylene terephthalate film used as the support in Example 1, but the haze value of the ink receiving layer was smaller than that of Example 1 and the transparency was low. The image sharpness due to transmitted light is good in both Examples 1 and 2,
The fingerprint resistance and ink absorption were also good. Example 3 in which the surfactant was replaced with one having an HLB value of 4.7 to 7.3 in Example 2 and the amount was increased was almost as good as Example 2. Example 4 is a case where fumed silica was omitted in Example 2 and fumed silica having an average primary particle size of 7 nm alone was used.
The image clarity is improved, and the glare is increased, but the fingerprint resistance,
The ink absorption was good. Example 5 is a case in which 2 parts of a surfactant having an HLB value of 4.7 is used for the swellable ink receiving layer. The contact angle with water is as high as 35 degrees, and the contact angle with linseed oil is also 20 degrees. Therefore, fingerprint resistance and ink absorption were the lower limits of actual use. Example 6 was a case where zirconium acetate was omitted in Example 1, but the haze value was slightly high and the transparency was lowered, but other characteristics were good. Example 7 is a case where 10 parts of a high boiling point organic solvent was used in place of the surfactant in Example 2, but the contact angle with water was as high as 30 degrees,
The fingerprint resistance and the ink absorption were reduced, the haze value was also increased, and the transparency was lowered, which was the practical lower limit. Example 8 is a case where the surfactant was changed from HLB value 4.7 to 10.5 in Example 2 and the amount was increased, but the fingerprint resistance was lower than in Example 2, but the lower limit of actual use was Met. In Example 9, the surfactant, dimethyldiallylammonium chloride homopolymer was removed from the composition of the ink receiving layer in Example 2,
In the case where the amount of polyvinyl alcohol was reduced and styrene / butadiene latex was used, the fingerprint resistance and the ink absorption were reduced, but they were practically usable.

Comparative Example 1 was a case where the surfactant was omitted in Example 1, but the contact angle with linseed oil was as high as 23 degrees, so that the fingerprint resistance was inferior. Comparative Example 2 is a case where the surfactant was removed in Example 5, but the contact angle with water and the contact angle with linseed oil were high, the fingerprint resistance was inferior to the lower limit of actual use, and the ink absorption was also reduced. At the lower limit. Comparative Example 3 is a case where an oil-in-water type acrylic emulsion was contained in the swellable ink receiving layer, but the contact angle with linseed oil was large,
Inferior in fingerprint resistance and unusable.

[0092]

As is evident from the above results, the present invention has good fingerprint resistance, high transparency (low haze value), and high ink absorption, and is particularly used in a backlight system in medical applications. Thus, an ink jet recording material free from glare caused by return light can be obtained.

Claims (6)

[Claims] 1. An ink-jet recording material comprising an ink-receiving layer provided on a light-transmitting support, wherein the surface of the recording material has a contact angle of 13 to 35 degrees with water and a contact angle of 8 minutes with linseed oil.
An ink jet recording material characterized by being at an angle of about 20 degrees. 2. The ink receiving layer according to claim 1, wherein the ink receiving layer comprises a hydrophilic polymer and H.
2. The ink jet recording material according to claim 1, comprising a surfactant having an LB value of 3 to 8. 3. The ink receiving layer according to claim 1, wherein the ink receiving layer comprises inorganic fine particles having an average primary particle diameter of 5 to 50 nm, a hydrophilic polymer, and HL.
2. The ink jet recording material according to claim 1, further comprising a surfactant having a B value of 3 to 8. 4. The ink jet recording material according to claim 3, wherein the inorganic fine particles are fumed silica. 5. The ink jet recording material according to claim 1, wherein the ink receiving layer has a contact angle with linseed oil of 8 to 15 degrees. 6. The ink receiving layer has an average particle size of 0.5 μm.
2. The method according to claim 1, wherein said inorganic pigment is contained.
6. The ink jet recording material according to any one of items 1 to 5,