JP2010125835A - Ink jet recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink jet recording medium which can record an image superior in a black printing density and which is half glossy. <P>SOLUTION: The ink jet recording medium includes ink accepting layers on a non-absorbency support. At least one layer of the ink accepting layers contains inorganic minute particle, polyvinyl alcohol having a saponification degree of less than 90 mol%, cellulose polymer, and cationic polyurethane resin, and the gross content of the cellulose polymer in the ink accepting layer is 0.1 to 1.1 mass% based on the total mass of the inorganic minute particle. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ink jet recording medium.

  In recent years, with the rapid development of the information industry, various information processing systems have been developed, and recording methods and apparatuses suitable for the information processing systems have been developed and put into practical use. Among the above recording methods, the inkjet recording method is capable of recording on various recording media, the hardware (device) is relatively inexpensive, is compact, has excellent quietness, and the like. Of course, it has been widely used in so-called home use.

In addition, with the recent increase in resolution of inkjet printers and the development of hardware (devices), various types of inkjet recording media have been developed, and in recent years it has become possible to obtain so-called photographic-like high-quality recorded matter. .
In particular, the characteristics required for ink jet recording media generally include (1) fast drying (high ink absorption speed), and (2) proper and uniform ink dot diameter (similar to (3) Good granularity, (4) High dot roundness, (5) High color density, (6) High saturation (no blurring) (7) The light resistance, gas resistance and water resistance of the printed part are good, (8) the whiteness of the recording surface is high, and (9) the preservability of the recording medium is good (yellow during long-term storage). No discoloration, image does not bleed after long-term storage), (10) good deformation and good dimensional stability (curl is sufficiently small), and (11) good hard running performance. Etc. In addition to the above properties, glossy paper, surface smoothness, and photographic paper-like texture similar to silver salt photography are also required for photo glossy paper used for the purpose of obtaining so-called photo-like high-quality recorded material. Is done.

In relation to the above, various ink jet recording media have been disclosed.
For example, as an ink-jet recording medium which is said to have good glossiness and printing density while maintaining little blurring of the image and less ink-receiving layer, fine particles, cationic polyurethane resin, water-soluble metal salt on the support An ink jet recording medium having an ink receiving layer containing a compound and a water-soluble resin and having a cationic polyurethane resin coating amount of 0.3 to 5 g / m ² is disclosed (for example, see Patent Document 1).

In addition, it has a relatively high glossiness, and when it is printed with an ink jet, the glossiness is further increased to give a high-quality print, so that it has an ink absorbing layer composed of at least two void layers, and other than the outermost layer. An ink jet recording medium is disclosed in which latex polymer particles are added to at least one of the void layers, and latex polymer particles are not substantially added to the void layer farthest from the support (see, for example, Patent Document 2).
In addition, an inorganic fine particle having an average particle diameter of 5 to 100 nm on a support and a cationic fixing agent as an ink jet recording medium having high gloss, having both an ink absorption speed and flexibility of an ink absorption layer, and having a high image density and hardly bleeding. , A binder, and an ink jet recording sheet having an ink absorption layer containing a polymer dispersion having a Tg of −50 to 40 ° C. and an average particle size of 5 nm or more and less than 50 nm are disclosed (for example, see Patent Document 3). .

In addition, it has good ink absorbency and glossiness, can form high-resolution and high-density images, has excellent image area preservability (light resistance, ozone resistance, etc.), and is aging at high temperatures and high humidity. As an ink-jet recording medium that is free from occurrence of water, fine particles, water-soluble resin, crosslinking agent, and water dispersion of cationic urethane resin having Tg of 50 ° C. or higher and an average particle size of 0.05 μm or less on the support An ink jet recording medium formed by using a coating liquid containing an object is disclosed (for example, see Patent Document 4).
JP 2004-351541 A Japanese Patent Laid-Open No. 2002-362023 JP 2003-63130 A JP 2004-195969 A

On the other hand, in recent years, a semi-glossy ink jet recording medium that can suppress fingerprint marks when the surface is pressed with a finger may be required. In addition, since the gloss is too high, a semi-glossy ink jet recording medium may be required for reasons such as the printed material being difficult to see depending on the viewing angle, the glare feeling being strong, and being unfriendly to the eyes.
However, the ink jet recording media described in Patent Documents 1 to 4 have a problem in obtaining a semi-gloss ink jet recording medium even though the glossiness can be increased.
An object of the present invention is to provide an ink jet recording medium that has an excellent black print density, has less blurring, and is capable of recording a semi-glossy image.

<1>
An ink-receiving layer on a non-absorbing support, wherein at least one of the ink-receiving layers contains inorganic fine particles, polyvinyl alcohol having a saponification degree of less than 90 mol%, a cellulosic polymer, and a cationic polyurethane resin; The total content of the cellulose polymer in the ink receiving layer is 0.1 to 1.1% by mass with respect to the total mass of the inorganic fine particles.
<2>
The ink jet recording medium according to <1>, wherein the total content of the cationic polyurethane resin is 3 to 7% by mass with respect to the total mass of the inorganic fine particles.
<3>
The ink jet recording medium according to <1> or <2>, wherein a primary particle diameter of the inorganic fine particles is less than 10 nm.
<4>
A layer having two or more ink-receiving layers on the non-absorbing support, wherein the content of the cationic polyurethane resin in the layer close to the non-absorbing support is farther from the non-absorbing support than the layer The inkjet recording medium according to any one of <1> to <3>, wherein the content is greater than
<5>
The inkjet recording medium according to any one of <1> to <4>, wherein the water-resistant support has a 60 ° glossiness of 40% or more.

  According to the present invention, it is possible to provide an ink jet recording medium that is excellent in black print density, has little blurring, and can record a semi-glossy image.

≪Inkjet recording medium≫
The ink jet recording medium of the present invention has at least one ink receiving layer on a non-absorbing support, and the ink receiving layer includes inorganic fine particles, polyvinyl alcohol having a saponification degree of less than 90 mol%, a cellulose polymer, And the total content of the cellulosic polymer in the ink receiving layer is 0.1 to 1.1% by mass with respect to the total mass of the inorganic fine particles. To do.
According to the present invention, an ink jet recording medium having the above-described configuration can provide an ink jet recording medium that is excellent in black print density and capable of recording a semi-glossy image.

  Furthermore, the ink receiving layer of the ink jet recording medium of the present invention can contain a crosslinking agent, a mordant, other additives, and the like, if necessary. Further, another layer may be provided on the support.

<Semi-glossy>
The ink receiving layer constituting the ink jet recording medium of the present invention has image clarity (total image sharpness), that is, optical combs used for measurement, 0.125 mm, 0.25 mm, 0.5 mm as glossiness after image recording. , 1.0 mm, or 2.0 mm, each value (image definition) is configured to satisfy the characteristic that the sum is less than 130.
That is, in the present invention, the “semi-gloss” means that the image clarity is less than 130.

  The image clarity is a measure of gloss, and if this measure shows a large value, it contributes to the gloss. In the present invention, the image clarity is an optical component having a frequency ranging from a low frequency to a high frequency including the main frequency range. By adopting a configuration that represents the sum of comb values (image definition), that is, the entire image definition, it is possible to obtain an inkjet recording medium capable of acquiring a semi-gloss image that the observer feels good. it can.

In the present invention, the total image sharpness described above, specifically, each value when the optical comb used is 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm, or 2.0 mm (image sharpness). Degree) is less than 130. When the image clarity is regarded as the sum of a plurality of values in a wide frequency range as described above, if the sum is 130 or more, it is not always possible to obtain a glossy feeling that the observer feels semi-glossy.
The image clarity (total image sharpness) is preferably 40 or more and less than 130, and more preferably 50 or more and 100 or less. The lower limit is not limited, but is about 40, for example.

The image clarity (total image sharpness) according to the present invention is based on the image clarity test method defined in JIS H 8686-2 by the image clarity measuring instrument ICM-1 (manufactured by Suga Test Instruments Co., Ltd.). Sum of each value [%; image clarity C value] measured using optical combs of 2.0 mm, 1.0 mm, 0.5 mm, 0.25 mm, and 0.125 mm (= value C ^{1 at} 2.0 mm) Value C ^{2 at} +1.0 mm + value C ^{3 at} 0.5 mm + value C ^{4 at} 0.25 mm + value C ^{5 at} 0.125 mm).
The measurement / analysis conditions at this time are as follows. The measurement is performed on the image portion recorded using the ink for ink jet recording in both the main scanning direction and the sub-scanning direction of printing, and after determining the image clarity C value by the following formula a for each optical comb, each optical comb is measured. It can be obtained by adding the image clarity C value at to obtain the sum.
<Measurement and analysis conditions>
Clarity C value (%) = {(M−m) / (M + m)} × 100 Equation a
[In Formula a, M represents the highest wave height, and m represents the lowest wave height. ]
・ Measurement method: reflection ・ Measurement angle: 60 °

  In the above, the image clarity (total image sharpness) according to the present invention is not a characteristic of the ink jet recording medium before recording, and each of the image recording needs to satisfy the above range after image recording. That is, a solid black image that is ink-jet-recorded under specific recording conditions is used as a measurement sample used for measurement of image clarity (total image sharpness).

The specific recording condition refers to a condition in which G-800 manufactured by Seiko Epson Corporation is used as a printer and recording is performed under the following conditions.
・ Paper settings: EPSON photo paper ・ Image quality settings: Recommended settings <Premium>
-Paper size: L size, with edges-Image data: Uncompressed image with 8-bit RGB data-Image data: Uniform image data with R = 0, G = 0, B = 0 (numeric values are decimal digits) Image size, resolution: 5cm x 5cm, 720dpi
-Humidity before printing: 23 ° C, 50% RH, 6 hours or more-Drying conditions until measurement of image clarity after printing: Drying at 23 ° C, 50% RH for 24 hours

  Hereinafter, the ink receiving layer, the components of the ink receiving layer, the other layers, and the non-absorbing support in the invention will be described.

<Ink receiving layer>
The ink jet recording medium in the present invention has a structure having at least one ink receiving layer on a non-absorbing support, but it is also a preferable aspect to have two or more ink receiving layers.
Each of these ink receiving layers may have a single layer structure or a plurality of layers.

(Inorganic fine particles)
The ink receiving layer in the invention contains at least one inorganic fine particle.
In the present invention, when there are two or more ink receiving layers, the inorganic fine particles contained in each layer may be the same or different.
As the inorganic fine particles, inorganic pigment fine particles are suitable. Examples of the inorganic pigment fine particles include silica fine particles, colloidal silica, titanium dioxide, barium sulfate, calcium silicate, zeolite, kaolinite, halloysite, mica, talc, carbonic acid. Calcium, magnesium carbonate, calcium sulfate, boehmite, pseudoboehmite and the like can be mentioned, and silica fine particles are particularly preferable from the viewpoint of ink absorbability and high color developability.

  Since the silica fine particles have a particularly large specific surface area, the ink absorbency and retention efficiency are high, and the refractive index is low, so that dispersion to an appropriate fine particle diameter can impart appropriate transparency to the ink receiving layer. There is an advantage that a high color density and good color developability can be obtained. As described above, when the ink receiving layer has appropriate transparency, the versatility of its use is increased, which is important from the viewpoint of obtaining a high color density, good color developability and glossiness.

  The average primary particle diameter of the inorganic pigment fine particles is preferably 20 nm or less, more preferably 15 nm or less, and particularly preferably 10 nm or less. When the average primary particle diameter is 20 nm or less, the ink absorption characteristics can be effectively improved, and at the same time, the glossiness of the surface of the ink receiving layer can be adjusted. It becomes remarkable and preferable.

  In particular, the silica fine particle has a silanol group on the surface thereof, and the particles are likely to adhere to each other due to the hydrogen bond of the silanol group, and because of the adhesion effect between the particles via the silanol group and the water-soluble resin, In the case where the average primary particle size is 20 nm or less (particularly 10 nm or less), the ink receiving layer has a large porosity and a highly transparent structure can be formed, thereby effectively improving the ink absorption characteristics. Can do.

  Generally, silica fine particles are roughly classified into wet method particles and dry method (gas phase method) particles depending on the production method. In the above wet method, a method is mainly used in which activated silica is produced by acid decomposition of a silicate, and this is appropriately polymerized and agglomerated and precipitated to obtain hydrous silica. On the other hand, the gas phase method is a method by high-temperature gas phase hydrolysis of silicon halide (flame hydrolysis method), a method in which silica sand and coke are heated and reduced by an arc in an electric furnace and oxidized with air. The method of obtaining anhydrous silica by the (arc method) is the mainstream, and the “gas phase method silica” refers to anhydrous silica fine particles obtained by the gas phase method.

Vapor phase method silica is different from the above hydrous silica in the density of silanol groups on the surface, the presence or absence of vacancies, etc., and shows different properties, but is suitable for forming a three-dimensional structure with high porosity. The reason for this is not clear, but in the case of hydrous silica, the density of silanol groups on the surface of the fine particles is as high as 5 to 8 / nm ^2, and the silica fine particles tend to aggregate (aggregate) easily, In the case of the method silica, the density of silanol groups on the surface of the fine particles is as small as ² to 3 / nm ² , so that it becomes sparse soft agglomeration (flocculate), and as a result, it is estimated that the structure has a high porosity. The
In the present invention, vapor phase silica fine particles (anhydrous silica) obtained by the dry method are preferable, and silica fine particles having a density of 2 to 3 silanol groups / nm ² on the surface of the fine particles are more preferable.

(Polyvinyl alcohol)
The ink receiving layer in the invention contains at least one polyvinyl alcohol having a saponification degree of less than 90% (hereinafter also simply referred to as polyvinyl alcohol). Thereby, application | coating failure can be suppressed and image clarity can be improved.
In the present invention, when there are two or more ink receiving layers, the polyvinyl alcohol contained in each layer may be the same or different.

The polyvinyl alcohol has a number average degree of polymerization of preferably 1800 to 4000, more preferably 2000 to 3500, from the viewpoint of preventing cracks.
When the saponification degree of the polyvinyl alcohol is 90% or more, a coating failure occurs and the image clarity is deteriorated.
When combined with silica fine particles, the type of water-soluble resin is important from the viewpoint of transparency. In particular, when anhydrous silica is used, polyvinyl alcohol contained as one of the water-soluble resins preferably has a saponification degree of 60% to less than 90%, particularly saponification, from the viewpoint of forming a three-dimensional network structure. Polyvinyl alcohol with a degree of less than 70-90% is preferred.

  The polyvinyl alcohol may be used alone or in combination of two or more.

  The polyvinyl alcohol has a hydroxyl group in the structural unit. The hydroxyl group and a silanol group on the surface of the silica fine particle form a hydrogen bond to form a three-dimensional network structure in which the secondary particle of the silica fine particle is a chain unit. Make it easier. By forming such a three-dimensional network structure, it is considered that an ink receiving layer having a porous structure with a high porosity can be formed.

As the total content in the ink receiving layer of polyvinyl alcohol is preferably ^{0.1~3.0g / m 2, 0.5~1.0g / m} 2 is more preferable.

(Cellulose polymer)
The ink receiving layer in the present invention contains at least one cellulosic polymer, and the total content of the cellulosic polymer is 0.1 to 1.1% by mass based on the total mass of the inorganic fine particles. There is a need to. In the structure of this invention, by using this in the said range, the viscosity stability of a coating liquid can improve, a coating failure can be suppressed, and a coating surface shape can be improved.
In the present invention, when there are two or more ink receiving layers, the cellulose-based polymer contained in each layer may be the same or different.

  The cellulose-based resin can be appropriately selected from known ones. For example, methyl cellulose (MC), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), carboxymethyl cellulose (CMC), hydroxypropyl cellulose (HPC) ), Hydroxypropyl methylcellulose (HPMC) and the like, and from the viewpoint of aging blur of the image, among them, methylcellulose (MC), hydroxyethylcellulose (HEC), hydroxypropylcellulose (HPC), hydroxypropylmethylcellulose (HPMC) are preferable, Furthermore, hydroxypropylcellulose (HPC) and hydroxypropylmethylcellulose (HPMC) are preferable.

The total content of the cellulose-based polymer in the ink receiving layer is 0.1 to 1.1% by mass with respect to the total mass of the inorganic fine particles, but 0.15 to 1.0% by mass. Preferably, 0.2 to 0.9 mass% is more preferable.
When the total content of the cellulosic polymer is less than 0.1% by mass, the viscosity stability of the coating solution is lowered, and a coating failure occurs. When the total content exceeds 1.1% by mass, Stability becomes higher than necessary, silica aggregation during coating and drying hardly occurs, and a semi-glossy surface cannot be obtained.

  The cellulosic polymer has a hydroxyl group in its structural unit, and this hydroxyl group and a silanol group on the surface of the silica fine particle form a hydrogen bond to form a three-dimensional network structure in which the secondary particle of the silica fine particle is a chain unit. Easy to form. By forming such a three-dimensional network structure, it is considered that an ink receiving layer having a porous structure with a high porosity can be formed. In addition, it has a function of adjusting aging blur of the color material.

In the ink receiving layer in the present invention, a water-soluble resin other than the polyvinyl alcohol in the present invention and the cellulose polymer in the present invention can be further added and used.
Examples of water-soluble resins that can be used in combination include resins having a hydroxyl group as a hydrophilic structural unit, such as polyvinyl alcohol (PVA) having a saponification degree other than the above range, cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol, and silanol-modified polyvinyl. Alcohol, polyvinyl acetal, chitins, chitosans, starch; resins having hydrophilic ether bonds, polyethylene oxide (PEO), polypropylene oxide (PPO), polyethylene glycol (PEG), polyvinyl ether (PVE); hydrophilic Examples thereof include polyacrylamide (PAAM) and polyvinylpyrrolidone (PVP), which are resins having an amide group or an amide bond. In addition, polyacrylic acid salts, maleic acid resins, alginic acid salts, gelatins and the like having a carboxyl group as a dissociable group can also be mentioned.
When the polyvinyl alcohol in the present invention and the cellulose polymer in the present invention are used in combination with the above-mentioned water-soluble resin that can be used in combination, the total of the polyvinyl alcohol and cellulose polymer in the present invention and the water-soluble resin that can be used in combination. 1-30 mass% is preferable, the ratio of the polyvinyl alcohol of this invention with respect to quantity is more preferable, 3-20 mass% is more preferable, and 6-12 mass% is especially preferable.

(Content ratio of inorganic fine particles and water-soluble resin)
In at least one ink receiving layer, inorganic fine particles (preferably silica fine particles; x) and a water-soluble resin such as polyvinyl alcohol of the present invention (in the case of using the above-mentioned water-soluble resin that can be used in combination, the polyvinyl alcohol in the present invention, Content ratio of cellulose-based polymer and the total amount of water-soluble resin used in combination (y) (PB ratio (x / y), inorganic fine particles based on 1 part by mass of water-soluble resin such as polyvinyl alcohol of the present invention) [Mass] greatly affects the film structure of the ink receiving layer. That is, as the PB ratio increases, the porosity, pore volume, and surface area (per unit mass) increase. Specifically, as the PB ratio (x / y), a decrease in film strength and cracking during drying caused by the PB ratio being too large are prevented, and the PB ratio is too small. From the viewpoint of preventing the gap from being easily blocked by the resin and preventing the ink absorbability from being lowered due to a decrease in the void ratio, 1.5 / 1 to 10/1 is preferable.

  Since stress may be applied to the ink jet recording medium when passing through the transport system of the ink jet printer, the ink receiving layer must have sufficient film strength. Further, when cutting into a sheet, the ink receiving layer needs to have sufficient film strength to prevent cracking and peeling of the ink receiving layer. From such a viewpoint, the PB ratio (x / y) is preferably 5/1 or less, and preferably 2/1 or more from the viewpoint of securing high-speed ink absorbability with an inkjet printer.

(Cationic polyurethane resin)
The ink receiving layer in the invention contains at least one cationic polyurethane resin. By adopting a constitution containing the cationic polyurethane resin, it is possible to obtain an ink jet recording medium exhibiting an appropriate image-rendering property that is semi-glossy and excellent in coated surface shape and blurring.
In the present invention, when there are two or more ink receiving layers, the cationic polyurethane resins contained in each layer may be the same or different.

The total content of the cationic polyurethane resin in the ink receiving layer in the invention is preferably 3 to 7% by mass, more preferably 4 to 6% by mass, based on the total mass of the inorganic fine particles. More preferably, it is 4.5-5.5 mass%.
When the total content of the cationic polyurethane resin is 3% by mass or more, blurring tends to be reduced, and when it is 7% by mass or less, the viscosity stability of the coating liquid is improved, and the coated surface shape tends to be good. Therefore, it is preferable from the viewpoint of the balance between the coated surface shape and the blurring.

In the case where the ink receiving layer in the present invention has two or more ink receiving layers on a non-absorbing support, the content (Pc) of the cationic polyurethane resin in the layer (lower layer) close to the non-absorbing support is low. The content (Pd) of the layer (upper layer) farther from the lower layer than the non-absorbable support is preferably larger (Pc> Pd). By adopting this configuration, it is preferable that the target image clarity is exhibited and there is not much blurring. The ratio of the content in the upper layer of the cationic polyurethane resin to the content in the lower layer (Pc: Pd) is preferably 100: 0 to 60:40, and more preferably 100: 0 to 80:20.
As described above, the total content of the cationic polyurethane resin in the two or more ink receiving layers is in the range of 3 to 7% by mass.

  When the cationic polyurethane resin is used together with the cellulosic polymer in the present invention, the coating property becomes particularly good and coating failure can be suppressed. The suppression effect becomes remarkable.

  The cationic polyurethane resin used in the present invention is not particularly limited, and various known ones can be used, and examples thereof include cationic polyurethane resins obtained by the following preparations (1) and (2). In particular, a composition in which a cationic polyurethane resin is dispersed in water as cationic polyurethane resin particles, that is, an aqueous dispersion is preferable.

  The cationic polyurethane resin is prepared by (1) using a polyester polyol (B1) as a polyol for urethane reaction with the polyisocyanate (A), and using a chain extender (C) having a tertiary amino group as a urethane prepolymer. A cationic polyurethane resin is prepared by preparing a polymer and neutralizing a part of the tertiary amino group with an acid or quaternizing with a quaternizing agent so that the amine value is in the range of 1 to 40 (KOHmg / g). It can be obtained in the form of a composition. (2) Polycarbonate polyol (B2), chain extender (C) having a tertiary amino group, and polyalkylene oxide (D) containing 50% by weight or more of an ethylene oxide chain, the polyisocyanate (A) A cationic polyurethane resin can be obtained by preparing a urethane prepolymer using the above and neutralizing a tertiary amino group introduced by the chain extender (C) with an acid or quaternizing with a quaternizing agent. it can. By obtaining the cationic polyurethane resin in a form dispersed in water, it can be obtained as an aqueous dispersion.

  The cationic polyurethane is preferably polymerized by a soap-free polymerization method in terms of avoiding a decrease in print density due to wet heat.

  The amount of the quaternary amine of the cationic polyurethane is preferably 0.6 meq / g or more in order to make a complex with the dye in the ink and improve the bleeding.

  The particle diameter of the cationic polyurethane aqueous dispersion is preferably less than 50 nm. If it is 50 nm or more, the print density is lowered and the bleeding suppression power is lowered.

  The cationic polyurethane preferably has a Tg of less than 120 ° C. When Tg exceeds 120 ° C., the curling of the image receiving layer is deteriorated, and the brittleness of the image receiving layer tends to be lowered.

  The cationic polyurethane resin in the present invention can also be used in the form of the dispersion having the water-soluble resin.

  Moreover, the form which further contained the inorganic water absorbing material may be sufficient as the cationic polyurethane resin in this invention. Inorganic water-absorbing materials include light calcium carbonate, heavy calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium oxide, zinc oxide, zinc sulfate, zinc carbonate, satin white, aluminum silicate, diatomaceous earth, calcium silicate, none Examples thereof include regular silica, aluminum hydroxide, alumina, ritbon, etc. Amorphous silica is preferable from the viewpoint of printing speed and color developability.

  By using the cationic polyurethane resin of the present invention, it can be applied to a sheet of soft polyvinyl chloride, semi-rigid polyvinyl chloride, rigid polyvinyl chloride, PET, polypropylene, polyethylene or the like.

  For the cationic polyurethane resin in the present invention, the resins described in JP-A-2002-307811, paragraphs 0006 to 0048 and JP-A-2002-307812, paragraphs 0006 to 0053 can be used.

(Water-soluble metal salt compound)
The ink receiving layer of the ink jet recording medium of the present invention preferably contains a water-soluble metal salt compound.
By containing the water-soluble metal salt compound in the ink receiving layer, it is possible to improve the water resistance and aging resistance of the printed image.
Examples of the water-soluble metal salt compound used in the present invention include a water-soluble salt of a metal selected from calcium, barium, manganese, copper, cobalt, nickel, aluminum, iron, zinc, zirconium, chromium, magnesium, tungsten, and molybdenum. Is mentioned.
Specifically, 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, second chloride Copper, ammonium chloride (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, polyaluminum chloride, aluminum nitrate nonahydrate, aluminum chloride hexahydrate, ferrous bromide, ferrous chloride Iron, ferric chloride, ferrous sulfate, ferric sulfate, zinc bromide, zinc chloride, zinc nitrate hexahydrate Zinc sulfate, zirconium acetate, zirconium chloride, zirconium chloride oxide octahydrate, hydroxy zirconium chloride, chromium acetate, chromium sulfate, magnesium sulfate, magnesium chloride hexahydrate, magnesium citrate nonahydrate, sodium phosphotungstate Sodium tungsten citrate, 12 tungstophosphoric acid n hydrate, 12 tungstosilicic acid 26 hydrate, molybdenum chloride, 12 molybdophosphoric acid n hydrate, and the like.

The water-soluble metal salt compound is particularly preferably at least one selected from water-soluble aluminum compounds, zirconium compounds and titanium compounds.
As the aluminum compound, for example, aluminum chloride or a hydrate thereof, aluminum sulfate or a hydrate thereof, ammonium alum or the like is known as an inorganic salt. Furthermore, there is a basic polyaluminum hydroxide compound which is an inorganic aluminum-containing cationic polymer. In particular, a basic polyaluminum hydroxide compound is preferable.

The basic polyaluminum hydroxide compound has a main component represented by the following formula 1, 2 or 3, for example, [Al ₆ (OH) ₁₅ ] ³⁺ , [Al ₈ (OH) ₂₀ ] ⁴⁺ , [Al ₁₃ (OH) ₃₄ ] ⁵⁺ , [Al ₂₁ (OH) ₆₀ ] ³⁺ , and the like, which are water-soluble polyaluminum hydroxides that stably contain basic and high-molecular polynuclear condensed ions.

[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 Formula 3

  These are water treatment agents from Taki Chemical Co., Ltd. under the name of polyaluminum chloride (PAC), from Asada Chemical Co., Ltd. under the name of polyaluminum hydroxide (Paho), and from Riken Green Co., Ltd. It is marketed under the name of Purachem WT and from other manufacturers for the same purpose, and various grades can be easily obtained. In the present invention, these commercially available products can be used as they are, but there are also products having an inappropriately low pH, and in that case, the pH can be appropriately adjusted and used.

The zirconium compound used in the present invention is not particularly limited and various compounds can be used. For example, zirconium acetate, zirconium chloride, zirconium oxychloride, hydroxy zirconium chloride, zirconium nitrate, basic zirconium carbonate, zirconium hydroxide Zirconium carbonate / ammonium, zirconium carbonate / potassium, zirconium sulfate, zirconium fluoride compound and the like.
The titanium compound is not particularly limited and various compounds can be used. Examples thereof include titanium chloride and titanium sulfate.
Some of these compounds have an inappropriately low pH. In that case, the pH can be appropriately adjusted and used. In the present invention, the term “water-soluble” means that 1% by mass or more dissolves in water at room temperature and normal pressure.

  In the present invention, the content of the water-soluble metal salt compound in the ink receiving layer is preferably 0.1 to 10% by mass, more preferably 1 to 5% by mass with respect to the inorganic fine particles.

  Although the said water-soluble metal salt compound can be used individually, 2 or more types can also be used together.

(Crosslinking agent)
The ink receiving layer in the invention preferably contains inorganic fine particles, a water-soluble resin such as polyvinyl alcohol and a cellulose-based polymer, and a cross-linking agent capable of cross-linking the water-soluble resin. A porous layer cured by reaction is preferred.

As the crosslinking agent, a suitable one may be appropriately selected in relation to the water-soluble resin such as the polyvinyl alcohol and cellulose polymer contained in the ink receiving layer, but among them, the crosslinking reaction is quick. Boron compounds are preferred, for example, borax, boric acid, borates (eg, orthoborate, InBO ₃ , ScBO ₃ , YBO ₃ , LaBO ₃ , Mg ₃ (BO ₃ ) ₂ , Co ₃ (BO ₃ ) ₂ , diboric acid Salt (eg, Mg ₂ B ₂ O ₅ , Co ₂ B ₂ O ₅ ), metaborate (eg, LiBO ₂ , Ca (BO ₂ ) ₂ , NaBO ₂ , KBO ₂ ), tetraborate (eg, Na _{2 B 4 O 7 · 10H 2 O} ), five borate _{(e.g., KB 5 O 8 · 4H 2} O, Ca 2 B 6 O 11 · 7H 2 O, CsB 5 O 5) , and the like. in , In that it can cause a crosslinking reaction rapidly, boric acid, borax, borate are preferable, and boric acid is particularly preferred, it is most preferable to use this in combination with polyvinyl alcohol.

  In the present invention, the crosslinking agent is preferably contained in an amount of 0.05 to 0.50 parts by mass with respect to 1.0 part by mass of the water-soluble resin such as polyvinyl alcohol and cellulose polymer. More preferably, it is contained in an amount of 08 to 0.30 parts by mass. When the content of the crosslinking agent is in the above range, the water-soluble resin in the present invention can be effectively crosslinked to prevent cracks and the like.

When gelatin is used as the water-soluble resin, the following compounds other than boron compounds can also be used as a crosslinking agent.
For example, aldehyde compounds such as formaldehyde, glyoxal, and glutaraldehyde; ketone compounds such as diacetyl and cyclopentanedione; bis (2-chloroethylurea) -2-hydroxy-4,6-dichloro-1,3,5- Active halogen compounds such as triazine and 2,4-dichloro-6-S-triazine sodium salt; divinylsulfonic acid, 1,3-vinylsulfonyl-2-propanol, N, N′-ethylenebis (vinylsulfonylacetamide) ), Active vinyl compounds such as 1,3,5-triacryloyl-hexahydro-S-triazine; N-methylol compounds such as dimethylolurea and methyloldimethylhydantoin; melamine resins (for example, methylolmelamine, alkylated methylolmelamine) ;Epoxy resin;

  Isocyanate compounds such as 1,6-hexamethylene diisocyanate; Aziridine compounds described in US Pat. Nos. 3,017,280 and 2,983,611; Carboximide compounds described in US Pat. No. 3,100,704; Glycerol triglycidyl Epoxy compounds such as ether; Ethyleneimino compounds such as 1,6-hexamethylene-N, N′-bisethyleneurea; Halogenated carboxaldehyde compounds such as mucochloric acid and mucophenoxycyclolic acid; 2,3-dihydroxy Dioxane compounds such as dioxane; Titanium lactate, aluminum sulfate, chromium alum, potash alum, metal-containing compounds such as zirconyl acetate and chromium acetate, polyamine compounds such as tetraethylenepentamine, and hydrazide compounds such as adipic acid dihydrazide It is a small molecule or polymer or the like containing an oxazoline group two or more. The above crosslinking agents may be used alone or in combination of two or more.

  In the present invention, the cross-linking agent may be added to the ink receiving layer coating liquid and / or the coating liquid for forming the adjacent layer of the ink receiving layer when forming the ink receiving layer, or The above-mentioned coating solution for ink-receiving layer is coated on a support on which a coating solution containing a crosslinking agent has been applied in advance, or a coating solution for ink-receiving layer that does not contain a crosslinking agent is coated and dried, and then the coating solution is overcoated. For example, a crosslinking agent can be supplied to the ink receiving layer. Preferably, from the viewpoint of production efficiency, it is preferable to add a crosslinking agent to the ink receiving layer coating solution or the coating solution for forming the adjacent layer, and supply the crosslinking agent simultaneously with the formation of the ink receiving layer. In particular, it is preferably contained in the ink-receiving layer coating liquid from the viewpoint of improving the image printing density. Further, the concentration of the crosslinking agent in the ink receiving layer coating solution is preferably 0.05 to 10% by mass, and more preferably 0.1 to 7% by mass.

  For example, a crosslinking agent can be suitably applied as follows. Here, a boron compound will be described as an example. That is, when the ink receiving layer is a layer obtained by crosslinking and curing the coating layer coated with the ink receiving layer coating liquid (first coating liquid), the crosslinking curing is performed by (1) coating the coating layer by applying the coating liquid. (2) During the dry coating of the coating layer formed by coating the coating solution and before the coating layer exhibits a reduced rate of drying, the pH is 8 or more. This is performed by applying a basic solution (second coating solution) to the coating layer. The boron compound as the crosslinking agent may be contained in either the first coating liquid or the second coating liquid, or may be contained in both the first coating liquid and the second coating liquid.

(mordant)
In the present invention, a mordant can be contained in the ink receiving layer in order to improve the water resistance and aging resistance of the printed image. As the mordant, any of an organic mordant such as a cationic polymer (cationic mordant) and an inorganic mordant such as a water-soluble metal compound can be used. As the mordant, either an organic mordant or an inorganic mordant can be used. These mordants shall mean things other than the said water-soluble metal salt compound and the said cationic polyurethane resin. Of these, organic mordants are preferable, and cationic mordants are particularly preferable.

  The presence of the mordant in at least the upper layer of the ink receiving layer causes an interaction with an ink-jet liquid ink having an anionic dye as a coloring material, which stabilizes the coloring material, thereby improving water resistance and resistance. The aging blur can be further improved.

  In the case where the ink receiving layer is formed using the ink receiving layer coating liquid (first coating liquid) and the basic solution (second coating liquid), the ink receiving layer may be contained in either of them, but inorganic fine particles (especially It is preferable to use it in a second coating liquid that is a liquid separate from the liquid containing phase method silica). That is, when a mordant is added directly to a coating solution for an ink receiving layer, aggregation may occur in the presence of vapor phase silica having an anionic charge. Can be prepared independently and applied separately, there is no need to worry about agglomeration of inorganic fine particles, and the range of mordant species can be selected.

  Among these, it is particularly preferable to use a basic mordant (for example, polyallylamine). When a basic mordant is used, it plays a role as a mordant and also functions as a basic substance, and a basic solution can be prepared without using a basic substance.

As the cationic mordant, a polymer mordant having a primary to tertiary amino group or a quaternary ammonium base as a cationic group is preferably used, but a cationic non-polymer mordant may also be used. it can.
Examples of the polymer mordant include a homopolymer of a monomer having a primary to tertiary amino group and a salt thereof, or a monomer having a quaternary ammonium base (hereinafter referred to as “mordant monomer”), or the mordant monomer. And those obtained as a copolymer or a condensation polymer of the other monomer (hereinafter referred to as “non-mordant polymer”) are preferable. These polymer mordants can be used in any form of a water-soluble polymer or water-dispersible latex particles.

  Examples of the mordant monomer include trimethyl-p-vinylbenzylammonium chloride, trimethyl-m-vinylbenzylammonium chloride, triethyl-p-vinylbenzylammonium chloride, triethyl-m-vinylbenzylammonium chloride, N, N-dimethyl- N-ethyl-Np-vinylbenzylammonium chloride, N, N-diethyl-N-methyl-Np-vinylbenzylammonium chloride, N, N-dimethyl-Nn-propyl-Np-vinylbenzyl Ammonium chloride, N, N-dimethyl-Nn-octyl-Np-vinylbenzylammonium chloride, N, N-dimethyl-N-benzyl-Np-vinylbenzylammonium chloride, N, N-diethyl-N Benzyl-Np-vinylbenzylammonium chloride, N, N-dimethyl-N- (4-methyl) benzyl-Np-vinylbenzylammonium chloride, N, N-dimethyl-N-phenyl-Np-vinyl Benzylammonium chloride;

  Trimethyl-p-vinylbenzylammonium bromide, trimethyl-m-vinylbenzylammonium bromide, trimethyl-p-vinylbenzylammonium sulfonate, trimethyl-m-vinylbenzylammonium sulfonate, trimethyl-p-vinylbenzylammonium acetate, trimethyl-m-vinyl Benzylammonium acetate, N, N, N-triethyl-N-2- (4-vinylphenyl) ethylammonium chloride, N, N, N-triethyl-N-2- (3-vinylphenyl) ethylammonium chloride, N, N-diethyl-N-methyl-N-2- (4-vinylphenyl) ethylammonium chloride, N, N-diethyl-N-methyl-N-2- (4-vinylphenyl) ethylammonium chloride Tate;

  N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, N-diethylaminopropyl (meth) acrylate, N, N- Methyl chloride, ethyl chloride, methyl bromide of dimethylaminoethyl (meth) acrylamide, N, N-diethylaminoethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, N-diethylaminopropyl (meth) acrylamide , Quaternized products of ethyl bromide, methyl iodide or ethyl iodide, or sulfonates, alkyl sulfonates, acetates or alkyl carboxylates substituted with their anions.

  Specific examples of the compound include monomethyl diallylammonium chloride, trimethyl-2- (methacryloyloxy) ethylammonium chloride, triethyl-2- (methacryloyloxy) ethylammonium chloride, trimethyl-2- (acryloyloxy) ethylammonium chloride, Triethyl-2- (acryloyloxy) ethylammonium chloride, trimethyl-3- (methacryloyloxy) propylammonium chloride, triethyl-3- (methacryloyloxy) propylammonium chloride, trimethyl-2- (methacryloylamino) ethylammonium chloride, triethyl- 2- (methacryloylamino) ethylammonium chloride, trimethyl-2- (acryloylua) C) ethylammonium chloride, triethyl-2- (acryloylamino) ethylammonium chloride, trimethyl-3- (methacryloylamino) propylammonium chloride, triethyl-3- (methacryloylamino) propylammonium chloride, trimethyl-3- (acryloylamino) Propylammonium chloride, triethyl-3- (acryloylamino) propylammonium chloride;

N, N-dimethyl-N-ethyl-2- (methacryloyloxy) ethylammonium chloride, N, N-diethyl-N-methyl-2- (methacryloyloxy) ethylammonium chloride, N, N-dimethyl-N-ethyl- 3- (acryloylamino) propylammonium chloride, trimethyl-2- (methacryloyloxy) ethylammonium bromide, trimethyl-3- (acryloylamino) propylammonium bromide, trimethyl-2- (methacryloyloxy) ethylammonium sulfonate, trimethyl-3- And (acryloylamino) propylammonium acetate.
Other examples of the copolymerizable monomer include N-vinylimidazole and N-vinyl-2-methylimidazole.

In addition, allylamine, diallylamine, derivatives thereof, salts and the like can also be used. Examples of such compounds are allylamine, allylamine hydrochloride, allylamine acetate, allylamine sulfate, diallylamine, diallylamine hydrochloride, diallylamine acetate, diallylamine sulfate, diallylmethylamine and salts thereof (for example, Hydrochloride, acetate, sulfate, etc.), diallylethylamine and salts thereof (for example, hydrochloride, acetate, sulfate, etc.), diallyldimethylammonium salt (chloride, acetic acid as counter anions of the salt) Ion sulfate, etc.). In addition, since these allylamines and diallylamine derivatives are inferior in polymerizability in the amine form, it is a general production method to polymerize in the form of a salt and desalting as required.
In addition, a polymerization unit such as N-vinylacetamide, N-vinylformamide or the like, which is converted into a vinylamine unit by hydrolysis after polymerization, and a salt thereof can be used.

The non-mordant monomer does not contain a basic or cationic moiety such as a primary to tertiary amino group and a salt thereof, or a quaternary ammonium base, and does not interact with a dye in an inkjet ink. Or a monomer having a substantially small interaction.
Examples of the non-mordant monomer include (meth) acrylic acid alkyl ester; (meth) acrylic acid cycloalkyl ester such as cyclohexyl (meth) acrylate; (meth) acrylic acid aryl ester such as phenyl (meth) acrylate; Aralkyl esters such as (meth) benzyl acrylate; Aromatic vinyls such as styrene, vinyl toluene and α-methylstyrene; Vinyl esters such as vinyl acetate, vinyl propionate and vinyl versatic acid; Allyl esters such as allyl acetate Halogen-containing monomers such as vinylidene chloride and vinyl chloride; vinyl cyanide such as (meth) acrylonitrile; olefins such as ethylene and propylene; and the like.

  The (meth) acrylic acid alkyl ester is preferably a (meth) acrylic acid alkyl ester having 1 to 18 carbon atoms in the alkyl moiety, specifically, for example, methyl (meth) acrylate or ethyl (meth) acrylate. Propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, (meth) Examples include octyl acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, and the like. Among these, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, and hydroxyethyl methacrylate are preferable. The non-mordant monomers can be used alone or in combination of two or more.

  Furthermore, as a polymer mordant, polydiallyldimethylammonium chloride, polymethacryloyloxyethyl-β-hydroxyethyldimethylammonium chloride, polyethyleneimine, polyallylamine and its modified product, polyallylamine hydrochloride, polyamide-polyamine resin, cationized starch, Dicyandiamide formalin condensate, dimethyl-2-hydroxypropylammonium salt polymer, polyamidine, polyvinylamine, or acrylic silicon described in JP-A-10-264511, JP-A-2000-43409, JP-A-2000-343811, JP-A-2002-120452 Cationic acrylic emulsion of latex (trade name “Aquabrid series ASi-781, ASi-784, manufactured by Daicel Chemical Industries, Ltd.” ASi-578, ASi-903 ") and the like can also be mentioned as preferred, and polyallylamine and polyallylamine-modified products are particularly preferred.

  The polyallylamine-modified product is obtained by adding 2 to 50 mol% of acrylonitrile, chloromethylstyrene, TEMPO, epoxy hexane, sorbic acid or the like to polyallylamine, and preferably 5 to 5 of acrylonitrile, chloromethylstyrene, and TEMPO. It is a 10 mol% adduct, and 5 to 10 mol% TEMPO adduct of polyallylamine is particularly preferable from the viewpoint of exhibiting the effect of preventing ozone fading.

  The molecular weight of the mordant is preferably 2000 to 300,000 in terms of mass average molecular weight. When the molecular weight is within this range, the water resistance and aging resistance can be further improved.

(Other ingredients)
The ink receiving layer in the invention may contain the following components as necessary.
That is, for the purpose of suppressing the deterioration of the ink coloring material, various ultraviolet absorbers, antioxidants, anti-fading agents such as singlet oxygen quenchers may be included.
Examples of the ultraviolet absorber include cinnamic acid derivatives, benzophenone derivatives, benzotriazolylphenol derivatives, and the like. For example, α-cyano-phenyl cinnamate butyl, o-benzotriazole phenol, o-benzotriazole-p-chlorophenol, o-benzotriazole-2,4-di-t-butylphenol, o-benzotriazole-2,4 -Di-t-octylphenol etc. are mentioned. A hindered phenol compound can also be used as an ultraviolet absorber, and specifically, a phenol derivative in which one or more of at least 2-position or 6-position is substituted with a branched alkyl group is preferable.

  Moreover, a benzotriazole type ultraviolet absorber, a salicylic acid type ultraviolet absorber, a cyanoacrylate type ultraviolet absorber, an oxalic acid anilide type ultraviolet absorber, etc. can be used. For example, JP-A-47-10537, 58-111942, 58-21284, 59-19945, 59-46646, 59-109055, 63-53544. No. 36, Japanese Patent Publication No. 36-10466, No. 42-26187, No. 48-30492, No. 48-31255, No. 48-41572, No. 48-54965, No. 50-10726. No. 2,719,086, US Pat. No. 3,707,375, US Pat. No. 3,754,919, US Pat. No. 4,220,711, and the like. .

  A fluorescent brightening agent can also be used as an ultraviolet absorber, and examples thereof include a coumarin fluorescent brightening agent. Specifically, it is described in Japanese Patent Publication Nos. 45-4699 and 54-5324.

  Examples of the antioxidant include European Patent Publication No. 223739, Publication No. 309401, Publication No. 309402, Publication No. 310551, Publication No. 310552, Publication No. 4594416, Publication of German Patent No. 3435443, JP-A-54-48535, JP-A-60-107384, JP-A-60-107383, JP-A-60-125470, JP-A-60-125471, JP-A-60-125472, JP-A-60-287485. 60-287486, 60-287487, 60-287488, 61-160287, 61-185483, 61-2111079, 62-146678, 62-146680, 62-146679, 62-282885, JP same 62-262047, JP-same 63-051174, JP-same 63-89877, JP-same 63-88380, JP-same 66-88381, JP-same 63-113536 JP;

  JP-A-63-163351, JP-A-63-203372, JP-A-63-224989, JP-A-63-251282, JP-A-63-267594, JP-A-63-182484, JP-A-1-239282, JP-A-2-262654, JP-A-2-71262, JP-A-3-121449, JP-A-4-29185, JP-A-4-291684, JP-A-5-61166, JP-A-5-119449, 5-188687, 5-188686, 5-110490, 5-110437, 5-170361, JP 48-43295, 48-33212, Examples thereof include those described in U.S. Pat. Nos. 4,814,262 and 4,980,275.

  Specifically, 6-ethoxy-1-phenyl-2,2,4-trimethyl-1,2-dihydroquinoline, 6-ethoxy-1-octyl-2,2,4-trimethyl-1,2-dihydroquinoline 6-ethoxy-1-phenyl-2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline, 6-ethoxy-1-octyl-2,2,4-trimethyl-1,2,3 4, -tetrahydroquinoline, nickel cyclohexane acid, 2,2-bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) -2-ethylhexane, 2-methyl-4-methoxy-diphenylamine, Examples include 1-methyl-2-phenylindole.

  These anti-fading agents may be used alone or in combination of two or more. The anti-fading agent may be water-solubilized, dispersed, emulsified, or contained in microcapsules. The addition amount of the anti-fading agent is preferably 0.01 to 10% by mass of the ink receiving layer coating solution.

  In the present invention, the ink receiving layer preferably contains a high boiling point organic solvent for curling prevention. The high-boiling organic solvent is preferably a water-soluble one. Examples of the water-soluble high-boiling organic solvent include ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, glycerin, diethylene glycol monobutyl ether (DEGMBE), Triethylene glycol monobutyl ether, glycerin monomethyl ether, 1,2,3-butanetriol, 1,2,4-butanetriol, 1,2,4-pentanetriol, 1,2,6-hexanetriol, thiodiglycol, Examples include alcohols such as triethanolamine and polyethylene glycol (weight average molecular weight of 400 or less). Diethylene glycol monobutyl ether (DEGMBE) is preferred.

The content of the high-boiling organic solvent in the ink-receiving layer coating solution is preferably 0.05 to 1% by mass, particularly preferably 0.1 to 0.6% by mass.
In addition, for the purpose of improving the dispersibility of the inorganic pigment fine particles, various inorganic salts, pH adjusting agents, and the like may contain acids and alkalis.
Further, for the purpose of suppressing surface frictional charge and peeling charge, the metal oxide fine particles having electronic conductivity may contain various matting agents for the purpose of reducing the surface frictional characteristics.

<Other layers>
The ink jet recording medium of the present invention has a layer other than the ink receiving layer on the non-absorbent support, for example, if necessary, the uppermost layer (for example, a glossy expression layer such as a colloidal silica layer), an intermediate layer, a cushioning property, You may have the functional layer etc. which provided functions, such as antistatic property.

<Non-absorbent support>
The ink jet recording medium of the present invention comprises the above-described ink receiving layer on a non-absorbing support.
In the present invention, “non-absorptive” means that it does not absorb water and the solvent contained in the ink for ink jet recording, or that the absorbed amount is 0.3 g / m ² or less, and particularly does not absorb water. Say.
By using a non-absorbent support, deformation such as curling accompanying image recording is suppressed.

  In the present invention, the 60 ° glossiness of the side surface on which the ink-receiving layer of the non-absorbing support is formed is not particularly limited, but a semi-glossy product can be obtained by using either a high gloss support or a low gloss support. From the viewpoint of enabling production and expanding the range of selection of the non-absorbent support, it is preferably 40% or more, more preferably 45% to 95%, and more preferably 50% to 85%. More preferably. For the 60 ° glossiness in the present invention, a value measured using a digital variable glossmeter (manufactured by Suga Test Instruments Co., Ltd.) is adopted.

  As the non-absorbent support, either a transparent support made of a transparent material such as plastic or an opaque support made of an opaque material such as paper can be used. In order to make use of the transparency of the ink receiving layer, it is preferable to use a transparent support or a highly glossy opaque support. Further, a read-only optical disk such as CD-ROM or DVD-ROM, a write-once optical disk such as CD-R or DVD-R, or a rewritable optical disk may be used as a support, and an ink receiving layer may be provided on the label surface side. it can.

The material that can be used for the transparent support is preferably a material that is transparent and can withstand radiant heat when used in an OHP or backlight display. Examples of such materials include polyesters such as polyethylene terephthalate (PET); polysulfone, polyphenylene oxide, polyimide, polycarbonate, polyamide, and the like. Of these, polyesters are preferable, and polyethylene terephthalate is particularly preferable.
The thickness of the transparent support is not particularly limited, but is preferably 50 μm to 200 μm from the viewpoint of ease of handling.

  Specific examples of the highly glossy opaque support include the following supports.

For example, high gloss paper support such as art paper, coated paper, cast coated paper, baryta paper used for silver salt photographic support, etc .; polyesters such as polyethylene terephthalate (PET), nitrocellulose, cellulose acetate , Cellulose esters such as cellulose acetate butyrate, and plastic films such as polysulfone, polyphenylene oxide, polyimide, polycarbonate, and polyamide are made opaque by adding a white pigment or the like (surface calendering may be applied). Glossy film; or a support in which a polyolefin coating layer containing or not containing a white pigment is provided on the surface of a highly glossy film containing the various paper supports, the transparent support or the white pigment. Etc.
A white pigment-containing foamed polyester film (for example, foamed PET containing polyolefin fine particles and forming voids by stretching) can also be suitably exemplified. Furthermore, resin-coated paper used for silver salt photographic printing paper is also suitable.

Although there is no restriction | limiting in particular also about the thickness of the said opaque support body, 50 micrometers-300 micrometers are preferable at the point of the ease of handling.
In addition, it is preferable to use a surface of the support that has been subjected to corona discharge treatment, glow discharge treatment, flame treatment, ultraviolet irradiation treatment or the like in order to improve wettability and adhesion.

Next, a base paper used for a paper support such as resin-coated paper will be described.
The base paper is made from wood pulp as a main raw material and, if necessary, paper using synthetic pulp such as polypropylene or synthetic fibers such as nylon or polyester in addition to wood pulp. As the wood pulp, any of LBKP, LBSP, NBKP, NBSP, LDP, NDP, LUKP, NUKP can be used, but it is preferable to use more LBKP, NBSP, LBSP, NDP, LDP with a lot of short fibers. preferable. However, the ratio of LBSP and / or LDP is preferably 10% by mass to 70% by mass.

As the above-mentioned pulp, chemical pulp (sulfate pulp or sulfite pulp) with few impurities is suitably used, and a pulp whose whiteness is improved by performing a bleaching treatment is also useful.
In the base paper, sizing agents such as higher fatty acids and alkyl ketene dimers, white pigments such as calcium carbonate, talc and titanium oxide, paper strength enhancing agents such as starch, polyacrylamide and polyvinyl alcohol, fluorescent whitening agents, polyethylene glycols A water retaining agent such as a dispersant, a softening agent such as a quaternary ammonium, and the like can be appropriately added.

  The freeness of pulp used for papermaking is preferably 200 ml to 500 ml as defined by CSF, and the fiber length after beating is a 24 mesh residual mass% and 42 mesh residual as defined in JIS P-8207. 30% to 70% is preferable. The 4 mesh residue is preferably 20% by mass or less.

The basis weight of the base paper is preferably 30 g to 250 g, particularly preferably 50 g to 200 g. The thickness of the base paper is preferably 40 μm to 250 μm. The base paper can be given a high smoothness by calendering at the paper making stage or after paper making. The density of the base paper ^{0.7g / m 2 ~1.2g / m 2} (JIS P-8118) is generally used. Furthermore, the base paper stiffness is preferably 20 to 200 g under the conditions specified in JIS P-8143.

A surface sizing agent may be applied to the surface of the base paper. As the surface sizing agent, a sizing agent similar to the size that can be added to the base paper can be used.
The pH of the base paper is preferably 5 to 9 when measured by a hot water extraction method defined in JIS P-8113.

  The polyethylene covering the front and back surfaces of the base paper is mainly low-density polyethylene (LDPE) and / or high-density polyethylene (HDPE), but some other LLDPE, polypropylene, etc. can also be used.

  In particular, the polyethylene layer on the side on which the ink receiving layer is formed is obtained by adding rutile or anatase type titanium oxide, fluorescent whitening agent, ultramarine blue to polyethylene, as is widely done in photographic paper, Those having improved whiteness and hue are preferred. Here, as titanium oxide content, 3 mass%-20 mass% are generally preferable with respect to polyethylene, and 4 mass%-13 mass% are more preferable. Although the thickness of a polyethylene layer does not have limitation in particular, 10 micrometers-50 micrometers are suitable for both front and back layers. Further, an undercoat layer can be provided on the polyethylene layer in order to provide adhesion to the ink receiving layer. As the undercoat layer, aqueous polyester, gelatin and PVA are preferable. The thickness of the undercoat layer is preferably 0.01 μm to 5 μm.

  Polyethylene-coated paper can be used as glossy paper, or matte or silky surface that can be obtained with ordinary photographic printing paper by applying a so-called molding process when polyethylene is melt-extruded and coated on the base paper surface. Can also be used.

A back coat layer can be provided on the support, and examples of components that can be added to the back coat layer include a white pigment, an aqueous binder, and other components.
Examples of white pigments contained in the backcoat layer include light calcium carbonate, heavy calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, and aluminum silicate. , Diatomaceous earth, calcium silicate, magnesium silicate, synthetic amorphous silica, colloidal silica, colloidal alumina, pseudoboehmite, aluminum hydroxide, alumina, lithopone, zeolite, hydrous halloysite, magnesium carbonate, magnesium hydroxide, white inorganic pigment, styrene And organic pigments such as polyethylene plastic pigments, acrylic plastic pigments, polyethylene, microcapsules, urea resins, and melamine resins.

Examples of the aqueous binder used in the backcoat layer include styrene / maleate copolymer, styrene / acrylate copolymer, polyvinyl alcohol, silanol-modified polyvinyl alcohol, starch, cationized starch, casein, gelatin, carboxy Examples thereof include water-soluble polymers such as methyl cellulose, hydroxyethyl cellulose, and polyvinyl pyrrolidone, and water-dispersible polymers such as styrene butadiene latex and acrylic emulsion.
Examples of other components contained in the back coat layer include antifoaming agents, foam suppressors, dyes, fluorescent brighteners, preservatives, and water resistance agents.

(Preparation of inkjet recording medium)
The ink jet recording medium of the present invention is prepared by providing at least one ink receiving layer on a non-absorbing support, and a step of forming an ink receiving layer by applying a coating liquid for forming an ink receiving layer. It can manufacture with the manufacturing method which has this.
Specifically, the inkjet recording medium of the present invention is, for example, a coating containing at least inorganic fine particles, polyvinyl alcohol having a saponification degree of less than 90%, a cationic polyurethane resin, and a cellulose polymer on a non-absorbing support. It can be manufactured by a manufacturing method having a step of forming an ink receiving layer by applying a liquid.
The ink-receiving layer-forming coating liquid contains the constituent components described in the section of the inkjet recording medium.

In addition, when the ink jet recording medium of the present invention has two or more ink receiving layers, two or more ink receiving layer forming coating liquids may be formed by simultaneous multilayer coating. After applying and drying one type of coating liquid for forming the above ink-receiving layer, another type of coating liquid is further applied and dried, and the same process is performed for the number of coating liquids. By repeating the process, two or more kinds of target ink receiving layers can be formed.
The method for producing an ink jet recording medium of the present invention may further include other steps as necessary.
In the above production method, the ink receiving layer, the glossiness, the non-absorbing support and the like are as described in the description of the ink jet recording medium, and the preferred ranges are also the same.
Hereinafter, a manufacturing method in the case where the ink jet recording medium of the present invention has two ink receiving layers will be described, but even in the case where the ink receiving layer has a number of ink receiving layers other than the two ink receiving layers, the same manufacturing is performed. be able to.

<Application process>
In the method for producing an ink jet recording medium of the present invention, the first coating liquid and the second coating liquid are applied in an arrangement that becomes the first coating liquid and the second coating liquid when viewed from the non-absorbent support side. A process (hereinafter also referred to as “coating process”).
As a method of applying the first coating liquid and the second coating liquid (and other coating liquids used as necessary), the first coating liquid and the second coating liquid as viewed from the non-absorbent support side. There is no particular limitation as long as the coating method is in the order of the following.
For example, a sequential coating method (for example, a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a reverse coater, etc.) that coats one layer at a time, or a plurality of layers constituting the ink receiving layer may be used. A simultaneous multi-layer coating method (for example, a slide bead coater, a slide curtain coater, or the like) that coats almost simultaneously without providing a drying step may be used. Alternatively, for example, “Wet-On-Wet method” (hereinafter, “WOW method”) described in paragraph numbers 0016 to 0037 of JP-A-2005-14593 may be used.

Among the above, the simultaneous multilayer coating method is preferably used from the viewpoint that the characteristics required for each layer can be obtained efficiently and the production efficiency is excellent. That is, in the simultaneous multi-layer coating, by laminating each layer in a wet state, the component contained in each layer, for example, the upper layer (for example, the second ink receiving layer in the inkjet recording medium of the present invention) is changed to the lower layer (for example, the present invention). This is presumably because the composition of each layer is well maintained even after drying.
The simultaneous multilayer coating can be performed using a known coating apparatus, and examples thereof include a slide bead coater, a curtain flow coater, and an extrusion die coater.

  In the present invention, if necessary, another coating solution may be applied onto the second coating solution. Further, a barrier layer coating solution (intermediate layer coating solution) may be interposed between the coating solutions.

Here, a preferable coating amount of each coating solution will be described.
As solid content application amount of the 1st and 2nd coating liquid, 0.5-30 g / m < ² > is preferable and 1-20 g / m < ² > is more preferable.
Hereinafter, the first and second coating liquids and other coating liquids used as necessary will be described.

(First and second coating solutions)
Either of the first and second coating liquids contains inorganic fine particles, polyvinyl alcohol having a saponification degree of less than 90 mol%, a cellulose-based polymer, and a cationic polyurethane resin, and in the ink receiving layer coating liquid The total content of the cellulosic polymer is 0.1 to 1.1% by mass of the total mass of the inorganic fine particles, and may contain other components as necessary.
Other components used as necessary, such as inorganic fine particles and cationic polyurethane resin, contained in the first and second coating liquids are as described in the description of the ink receiving layer, and preferred ranges are also the same. is there.
In the present invention, the total solid content in the first coating liquid refers to all components excluding water from the first coating liquid. The same applies to other liquids.

  The first and second coating liquids are preferably acidic, and the pH is preferably 5.0 or less, more preferably 4.5 or less, and further preferably 4.0 or less. preferable. The pH of the first and second coating liquids can be adjusted by appropriately selecting the type and addition amount of the nitrogen-containing organic cationic polymer. Moreover, you may adjust by adding an organic or inorganic acid. When the pH of the first coating solution is 5.0 or less, for example, the crosslinking reaction of the water-soluble resin (binder) by the crosslinking agent (particularly boron compound) in the first coating solution can be more sufficiently suppressed. it can.

~ Examples of preparation methods of first and second coating liquids ~
In the present invention, the first and second coating liquids can be prepared, for example, as follows.
That is, after adding vapor phase method silica fine particles, a dispersant, and a zirconium compound in water and using a liquid-liquid collision type disperser (Ultimizer, manufactured by Sugino Machine),
It can be prepared by adding boric acid, an aqueous polyvinyl alcohol (PVA) solution, a cationic polyurethane resin, and a dispersant, and further adding the water-soluble aluminum compound and dispersing.
The water-soluble aluminum compound may be added by in-line mixing immediately before coating.
The obtained coating liquid is in a uniform sol state, and a porous ink-receiving layer having a three-dimensional network structure can be formed by applying the coating liquid onto a support by the following coating method and drying it.

  Moreover, water, an organic solvent, or these mixed solvents can be used as a solvent in each process. Examples of the organic solvent that can be used for this coating include alcohols such as methanol, ethanol, n-propanol, i-propanol, and methoxypropanol, ketones such as acetone and methyl ethyl ketone, tetrahydrofuran, acetonitrile, ethyl acetate, and toluene. It is done.

  The amount of the dispersant added to the fine particles is preferably 0.1% to 30%, more preferably 1% to 10%.

<Curing process>
In the method for producing an ink jet recording medium of the present invention, the coating layer formed by coating the first coating liquid and the second coating liquid,
(1) At the same time as applying at least the first coating liquid and the second coating liquid,
(2) At least during the drying of the coating layer formed by applying the first coating solution and the second coating solution, and before the coating layer exhibits reduced-rate drying,
In any of the cases, a curing step of applying a liquid containing a basic compound and crosslinking and curing the coating layer may be provided.

Examples of the method for applying the “liquid containing a basic compound” at the same time as “(1) at least the first coating liquid and the second coating liquid are applied” include the first coating liquid and the second coating liquid. It is preferable that the coating solution (the other coating solution if necessary) and the “liquid containing a basic compound” are simultaneously applied (multilayer coating) in this order from the support side.
Alternatively, after the first coating liquid is applied, the second coating liquid and the “liquid containing a basic compound” are simultaneously applied onto the applied first coating liquid (hereinafter referred to as “simultaneous multilayer coating”). You may say).
The simultaneous coating (simultaneous multilayer coating) can be performed using a known coating device such as an extrusion die coater or a curtain flow coater.

“(2) Basic compound in the middle of drying of the coating layer formed by applying at least the first coating solution and the second coating solution and before the coating layer exhibits reduced-rate drying” The method of applying the “liquid containing” is a method called “Wet-On-Wet method” or “WOW method”. Details of the “Wet-On-Wet method” are described, for example, in paragraph numbers [0016] to [0037] of JP-A-2005-14593.
In the present invention, the first coating liquid and the second coating liquid (and other coating liquids as necessary) are simultaneously applied (simultaneous multi-layer coating) so as to be in this order from the support side. Alternatively, after forming the coating layer by coating one layer at a time, before the coating layer is in the course of drying, and before the coating layer exhibits reduced-rate drying, (i) further “basic compound” (Ii) a method of spraying the “liquid containing a basic compound” by spraying or the like, (iii) the support on which the coating layer is formed in the “liquid containing a basic compound” And a method of immersing in water.

  In the above (i), as a coating method for applying the “liquid containing a basic compound”, for example, curtain flow coater, extrusion die coater, air doctor coater, bread coater, rod coater, knife coater, squeeze coater, reverse A known coating method such as a roll coater or a bar coater can be used. However, it is preferable to use a method in which the coater does not directly contact an already formed coating layer, such as an extrusion die coater, a curtain flow coater, a bar coater or the like.

  In the cross-linking curing step, “before the coating layer comes to show reduced-rate drying” usually means an ink-receiving layer coating solution (in the present invention, the first coating solution and the second coating solution ( Furthermore, it refers to a process for several minutes immediately after the application of other coating liquids)) as necessary, during which the content of the solvent (dispersion medium) in the coated coating layer decreases in proportion to time. The phenomenon of “constant rate drying” is shown. About the time which shows this "constant rate drying", it describes in chemical engineering handbook (pages 707-712, Maruzen Co., Ltd. issue, October 25, 1980), for example.

  As a condition for the above-mentioned “drying until the coating layer exhibits reduced rate drying”, it is generally carried out at 40 to 180 ° C. for 0.5 to 10 minutes (preferably 0.5 to 5 minutes). The drying time naturally varies depending on the coating amount, but usually the above range is appropriate.

(Liquid containing basic compound)
Here, the “liquid containing a basic compound” in the crosslinking curing step will be described.
~ Basic compounds ~
The “liquid containing a basic compound” in the present invention contains at least one basic compound.
Basic compounds include ammonium salts of weak acids, alkali metal salts of weak acids (eg, lithium carbonate, sodium carbonate, potassium carbonate, lithium acetate, sodium acetate, potassium acetate, etc.), alkaline earth metal salts of weak acids (eg, carbonate Magnesium, barium carbonate, magnesium acetate, barium acetate, etc.), hydroxyammonium, primary to tertiary amines (eg, triethylamine, tripropylamine, tributylamine, trihexylamine, dibutylamine, butylamine, etc.), primary to tertiary anilines ( For example, diethylaniline, dibutylaniline, ethylaniline, aniline, etc.), pyridine which may have a substituent (for example, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 4- (2-hydroxyethyl) -Aminopyrid Etc.), and the like.

  In addition to the basic compound, other basic substances and / or salts thereof may be used in combination with the basic compound. Examples of other basic substances include ammonia, primary amines such as ethylamine and polyallylamine, secondary amines such as dimethylamine, tertiary amines such as N-ethyl-N-methylbutylamine, and alkali metals. And alkaline earth metal hydroxides.

Among the above, ammonium salts of weak acids are particularly preferable. The weak acid is an inorganic acid or an organic acid described in Chemical Handbook Fundamentals II (Maruzen Co., Ltd.) or the like and having an pKa of 2 or more. Examples of the weak acid ammonium salt include ammonium carbonate, ammonium hydrogen carbonate, ammonium borate, ammonium acetate, and ammonium carbamate. However, it is not limited to these. Among these, ammonium carbonate, ammonium hydrogen carbonate, and ammonium carbamate are preferable, and are effective in that ink bleeding can be reduced without remaining in the layer after drying.
Two or more basic compounds can be used in combination.

  The content of the basic compound (particularly the ammonium salt of a weak acid) in the “liquid containing the basic compound” is 0.5 to 0.5% relative to the total mass (including the solvent) of the “liquid containing the basic compound”. 10 mass% is preferable, More preferably, it is 1-5 mass%. When the content of the basic compound (particularly the ammonium salt of the weak acid) is particularly in the above range, a sufficient degree of curing can be obtained, and the ammonia concentration becomes too high without impairing the working environment.

~ Metal compound ~
The “liquid containing a basic compound” in the present invention preferably contains at least one metal compound.

  As the metal compound contained in the “liquid containing a basic compound”, those that are stable under basicity can be used without limitation, and the above-mentioned water-soluble polyvalent metal salts, metal complex compounds, inorganic oligomers, or inorganic polymers can be used. Any of these may be used. For example, zirconium compounds and compounds listed as inorganic mordants in paragraphs [0100] to [0101] of JP-A-2005-14593 are suitable. Examples of the metal complex compound include metal complexes described in “Chemistry Review No. 32 (1981)” edited by the Chemical Society of Japan, “Coordination Chemistry Review”, Vol. 84, pages 85-277. (1988) and JP-A-2-182701, transition metal complexes containing a transition metal such as ruthenium can be used.

  Among the above, zirconium compounds and zinc compounds are preferable, and zirconium compounds are particularly preferable. Examples of the zirconium compound include zirconium carbonate / ammonium, zirconium nitrate / ammonium, zirconium carbonate / potassium, zirconium citrate / ammonium citrate, zirconyl stearate, zirconyl octylate, zirconyl nitrate, zirconium oxychloride, and zirconium zirconium hydroxychloride. Particularly preferred is zirconium ammonium carbonate. Moreover, two or more metal compounds (preferably containing a zirconium compound) may be used in combination in the “liquid containing a basic compound”.

  As content in the "liquid containing a basic compound" of the said metal compound (especially zirconium compound), it is 0.05-5 mass% with respect to the total mass (a solvent is included) of "the liquid containing a basic compound". Is more preferable, and 0.1 to 2% by mass is more preferable. By setting the content of the metal compound (especially zirconium compound) in the above range, the coating layer can be sufficiently hardened, and the mordant ability is lowered, so that a sufficient printing density cannot be obtained, or beading is not achieved. It does not occur, and the working environment is not deteriorated due to the concentration of a basic compound such as ammonia becoming too high. Two or more metal compounds can be used in combination, and when other mordant components to be described later are used in combination with a metal compound other than the metal compound, the total amount is within the above range and does not impair the effects of the present invention. It can be contained in a range.

From the viewpoint of image density and ozone resistance, the “liquid containing a basic compound” preferably contains the aforementioned magnesium salt as a metal compound. As the magnesium salt, magnesium chloride is particularly preferable.
In this case, the addition amount of the magnesium salt is preferably 0.1 to 1% by mass and more preferably 0.15 to 0.5% by mass with respect to the total mass of the “liquid containing a basic compound”.

The “liquid containing a basic compound” can contain a crosslinking agent and other mordant components as necessary.
The “liquid containing a basic compound” can promote dura mater when used as an alkaline solution, and is preferably adjusted to pH 7.1 or higher, more preferably pH 8.0 or higher, and particularly preferably pH 9.0. That's it. When the pH is 7.1 or more, a crosslinking reaction of a water-soluble resin (binder) that may be contained in the first coating solution and / or the second coating solution can be further promoted, and bronzing and ink reception can be performed. Cracks in the layer can be more effectively suppressed.

  The “liquid containing a basic compound” includes, for example, ion-exchanged water, a metal compound (eg, zirconia compound; eg, 1 to 5%) and a basic compound (eg, ammonium carbonate; eg, 1 to 5%), It can be prepared by adding para-toluenesulfonic acid (for example, 0.5 to 3%) as necessary and stirring sufficiently. In addition, all "%" of each composition means solid content mass%.

  In addition, water, an organic solvent, or a mixed solvent thereof can be used as a solvent used for preparing the “liquid containing a basic compound”. Examples of the organic solvent that can be used for coating include alcohols such as methanol, ethanol, n-propanol, i-propanol, and methoxypropanol, ketones such as acetone and methyl ethyl ketone, tetrahydrofuran, acetonitrile, ethyl acetate, and toluene. .

<Cooling process, drying process>
In the method for producing an ink jet recording medium of the present invention, the coating layer formed in the coating layer forming step is any one of a temperature of the first coating liquid at the time of coating and a temperature of the second coating liquid at the time of coating. A step of cooling so as to decrease by 5 ° C. or more with respect to the lower one (hereinafter also referred to as “cooling step”) and a step of drying the cooled coating layer to form an ink receiving layer (hereinafter referred to as “drying step”) May be included).

As a method for cooling the coating layer in the cooling step, the support on which the coating layer is formed is cooled for 5 to 30 seconds in a cooling zone maintained at 0 to 10 ° C. (more preferably 0 to 5 ° C.). Is preferred.
Here, the temperature of the coating layer is measured by measuring the temperature of the film surface.

<Other processes>
In the present invention, after the ink receiving layer is formed on the support, the ink receiving layer is subjected to, for example, super calender, gloss calender, etc., and is subjected to calender treatment through the roll nip under heat and pressure, thereby surface smoothness. It is possible to improve glossiness, transparency and coating strength. However, the calendar process may cause a decrease in the porosity (that is, the ink absorptivity may be decreased), so it is necessary to set conditions under which the decrease in the porosity is small.

As roll temperature in the case of performing a calendar process, 30-150 degreeC is preferable and 40-100 degreeC is more preferable.
Moreover, as a linear pressure between rolls at the time of a calendar process, 50-400 kg / cm is preferable and 100-200 kg / cm is more preferable.

EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is not limited by the following Example. Unless otherwise specified, “part” and “%” in the examples are based on mass.
[Example 1]
(Preparation of non-absorbable support)
50 parts of LBKP made of acacia and 50 parts of LBKP made of aspen were each beaten to 300 ml of Canadian freeness by a disc refiner to prepare a pulp slurry.
Subsequently, to the pulp slurry obtained as described above, 1.3% of cationic starch (made by NSC Japan, CAT0304L), 0.15% anionic polyacrylamide (made by Seiko Chemical Co., Ltd., polyaclon ST-13) per pulp. After adding 0.29% of alkyl ketene dimer (Arakawa Chemical Co., Ltd., Size Pine K), 0.29% of epoxidized behenamide, 0.32% of polyamide polyamine epichlorohydrin (Arakawa Chemical Co., Ltd., Arafix 100) Antifoam 0.12% was added.

In the process of making the pulp slurry prepared as described above with a long paper machine and pressing the felt surface of the web against the drum dryer cylinder through the dryer canvas for drying, the tensile force of the dryer canvas is 1.6 kg / kg. After drying by setting to cm, 1 g / m ² of polyvinyl alcohol (manufactured by Kuraray Co., Ltd., KL-118) was applied to both sides of the base paper with a size press, and the calendar treatment was performed. The base paper was made with a basis weight of 166 g / m ² to obtain a base paper (base paper) having a thickness of 160 μm.

After the corona discharge treatment was performed on the wire surface (back surface) side of the obtained base paper, high-density polyethylene was coated to a thickness of 30 μm using a melt extruder, and a thermoplastic resin layer comprising a mat surface was formed. (Hereinafter, this thermoplastic resin layer surface is referred to as a “back surface”). The thermoplastic resin layer on the back side is further subjected to corona discharge treatment, and then, as an antistatic agent, aluminum oxide (“Alumina Sol 100” manufactured by Nissan Chemical Industries, Ltd.) and silicon dioxide (manufactured by Nissan Chemical Industries, Ltd.). “Snowtex O”) was dispersed in water at a mass ratio of 1: 2 so that the dry weight was 0.2 g / m ² . Subsequently, the front side (the side opposite to the back side) was corona-treated and a polyethylene melt having a density of 0.93 g / m ² having 10% by mass of titanium oxide was used to obtain a density of 24 g / m ^2. To obtain a non-absorbent support.
The 60 ° glossiness of the non-absorbent support was 70%.

<Preparation of coating liquid A for forming an ink receiving layer>
(1) Gas phase method silica fine particles of the following composition A, (2) ion-exchanged water, (3) “Charol DC-902P”, and (4) “ZA-30” are made by CONTI-TDS (Dalton Co., Ltd.) ) And then finely dispersed at 130 MPa under pressure using an optimizer (manufactured by Sugino Machine Co., Ltd.) to obtain a dispersion A.
Thereafter, Dispersion A was heated to 45 ° C. and held for 20 hours. Next, (b) boric acid described below in dispersion A, (6) polyvinyl alcohol solution, (7) ion-exchanged water, (8) SC507, (9) Superflex 650-5, (10) Emulgen 109P was added at 30 ° C. to prepare a coating liquid A for forming an ink receiving layer.

-Dispersion A-
(1) Gas phase method silica fine particles 207.7 parts [AEROSIL300SV, manufactured by Nippon Aerosil Co., Ltd.]
(2) Ion-exchanged water 827.8 parts (3) "Charol DC-902P" 51.5% aqueous solution 18.2 parts [Dispersant, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.]
(4) "ZA-30" (water-soluble zirconium salt) 11.2 parts [Zirconyl acetate, manufactured by Daiichi Rare Element Chemical Co., Ltd.]

-Coating liquid A-
(A) Dispersion A 1065 parts (b) Boric acid (7.5% aqueous solution) [Crosslinking agent] 102 parts (c) Polyvinyl alcohol solution P1 605 parts (d) Ion-exchanged water 94 parts (e) SC507 (solid Min. 70%) 1.61 parts [polyalkylene polyamine / dimethylamine / epichlorohydrin polycondensate,
Made by Hymo Co., Ltd.)
(F) Superflex 650-5 (solid content 25%) 41.5 parts [cationic polyurethane fine particles, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.]
(G) “Emulgen 109P” 10% aqueous solution 13.2 parts [manufactured by Kao Corporation, HLB value 13.6]

The composition of the polyvinyl alcohol solution P1 is as shown in the following composition P1.
-Composition P1-
"PVA235" (PVA) 42.1 parts [manufactured by Kuraray Co., Ltd., saponification degree 87-89 mol%, polymerization degree 3,500]
Polyoxyethylene lauryl ether [surfactant] 7.0 parts [Emulgen 109P, 10% aqueous solution, HLB value 13.6, manufactured by Kao Corporation]
・ Diethylene glycol monobutyl ether 12.8 parts [Kyowa Hakko Chemical Co., Ltd., Butisenol 20P]
・ Hydroxypropylcellulose (HPC-SSL: Nippon Soda) 0.83 parts ・ Ion-exchanged water 544.1 parts

<Preparation of inkjet recording sheet>
After the corona discharge treatment is applied to the front surface (side on which the ink receiving layer is provided) of the non-absorbent support, the coating solution A is coated with polyaluminum chloride using a static mixer. The aqueous solution was added in-line, and then coated with a slide bead coater, and a coating film for forming an ink receiving layer was provided on the front surface.

The coating amount and details of the coating solution A and the polyaluminum chloride aqueous solution are as follows.
(Ink receiving layer)
・ Coating liquid A: 165 g / m ²
・ 4.6% polyaluminum chloride aqueous solution 11.4 g / m ²
[Daiming Chemical Co., Ltd., Alpha-in 83, highly basic polyaluminum chloride]
The obtained coating film was cooled at 5 ° C. for 1 minute, cooled and dried at 40 ° C. to obtain an ink receiving layer.
Thereby, an ink jet recording sheet provided with an ink receiving layer having a dry layer thickness of 35 μm was produced.

[Example 2]
Inkjet recording was carried out in the same manner as in Example 1 except that the amount of hydroxypropylcellulose (HPC) added in Example 1 was half that in Example 1 and the vapor phase silica fine particle concentration was adjusted to be the same as in Example 1. A sheet was obtained.

Example 3
In Example 1, an inkjet recording sheet was obtained in the same manner as Example 1 except that (9) 4% of Superflex 650-5 was added to the vapor phase silica fine particles.

Example 4
An ink jet recording sheet was obtained in the same manner as in Example 1, except that (9) 6% of Superflex 650-5 was added to the vapor phase silica fine particles.

Example 5
In Example 1, a coating solution in ion-exchanged water was used for the upper layer instead of (9) Superflex 650-5 in Example 1, and the amount of (9) Superflex 650-5 in Example 1 was adjusted. Using the coating solution prepared by adjusting the vapor phase method silica fine particles to 10% with respect to the phase method silica fine particles in the same manner as in Example 1 for the lower layer, the above-described upper layer and lower layer coating solutions are applied in Example 1. An ink jet recording sheet was obtained in the same manner as in Example 1 except that the amount was reduced to half and the 4.6% polyaluminum chloride aqueous solution added in-line was halved and simultaneously layered.

Example 6
In Example 2, instead of Example 9 to (9) Superflex 650-5, a coating solution in ion-exchanged water was used for the upper layer, and the amount of (9) Superflex 650-5 in Example 2 was changed. A coating solution prepared by adjusting the vapor phase silica fine particles to 10% with respect to the vapor phase silica fine particles in the same manner as in Example 1 was used for the lower layer, and the above-described upper layer and lower layer coating liquids were used as in Example 2. An ink jet recording sheet was obtained in the same manner as in Example 1 except that the coating amount was halved and the 4.6% polyaluminum chloride aqueous solution added in-line was halved and simultaneously layered.

Example 7
In Example 1, an ink jet recording sheet was obtained in the same manner as in Example 1 except that (9) Superflex 650-5 was added in an amount of 8% to the vapor phase silica fine particles.

Example 8
An ink jet recording sheet was obtained in the same manner as in Example 1, except that 0.7% of hydroxypropylcellulose (HPC) was added to the vapor phase silica fine particles.

Example 9
In Example 1, the addition amount of hydroxypropyl cellulose (HPC) was 0.7% with respect to the vapor phase silica fine particles, and (9) 8% of Superflex 650-5 was added with respect to the vapor phase silica fine particles. Obtained an inkjet recording sheet in the same manner as in Example 1.

Example 10
An ink jet recording sheet was obtained in the same manner as in Example 1 except that hydroxypropylcellulose (HPC) was changed to hydroxypropylmethylcellulose (HPMC).

[Comparative Example 1]
In Example 1, (6) Polyvinyl alcohol (PVA235) in the polyvinyl alcohol solution P1 was changed to JM33 (saponification degree 95 mol%, polymerization degree 3,300, manufactured by Nihon Vinegar Bipovar), as in Example 1. Thus, an ink jet recording sheet was obtained.

[Comparative Example 2]
In Example 1, an inkjet recording sheet was obtained in the same manner as in Example 1 except that (9) Superflex 650-5 was not added.

[Comparative Example 3]
In Example 1, an ink jet recording sheet was obtained in the same manner as Example 1 except that hydroxypropylcellulose (HPC) was not added.

[Comparative Example 4]
An ink jet recording sheet was obtained in the same manner as in Example 1 except that hydroxypropylcellulose (HPC) and (9) Superflex SF650-5 were not added.

[Comparative Example 5]
An ink jet recording sheet was obtained in the same manner as in Example 1 except that the addition amount of hydroxypropyl cellulose (HPC) in Example 1 was changed to 0.4%.

(Evaluation test)
The following evaluation tests were conducted on the ink jet recording sheets of Examples and Comparative Examples obtained above. The results are shown in Table 1 below.

(1) Image clarity For each of the inkjet recording sheets of the examples and comparative examples, a black (K) solid image using the inkjet printer (PM-G800, manufactured by Seiko Epson Corporation) under the following image recording conditions. Images were printed and measurement samples were prepared.
<Image recording conditions>
・ Paper settings: EPSON photo paper ・ Image quality settings: Recommended settings <Premium>
-Paper size: L size, with edges-Image data: Uncompressed image with 8-bit RGB data-Uniform image data with R = 0, G = 0, B = 0 (numeric values are decimal digits) Image size, resolution: 5cm x 5cm, 720dpi
-Humidity before printing: 23 ° C, 50% RH, 6 hours or longer-Drying conditions after image printing and measurement of specular reflection intensity: Drying at 23 ° C, 50% RH for 24 hours

Next, the solid image portion of each ink jet recording sheet was measured on the basis of the image clarity test method defined in JIS H 8686-2, using a image clarity measuring device ICM-1 (manufactured by Suga Test Instruments Co., Ltd.). Under the measurement and analysis conditions, the image clarity C value (%) was measured.
The measurement was performed in both the main scanning direction and the sub-scanning direction of printing. Then, the image clarity C value was obtained for each optical comb by the following formula a, and the image clarity C value at each optical comb was added to obtain the sum of image clarity.
In the following formula a, M represents the maximum wave height, and m represents the minimum wave height. Evaluation is based on the following criteria, and the results are shown in Table 1.
Image clarity C value (%) = {(M−m) / (M + m)} × 100 Equation a
<Measurement and analysis conditions>
・ Measurement method: reflection ・ Measurement angle: 60 °
Optical comb: 2.0 mm, 1.0 mm, 0.5 mm, 0.25 mm, 0.125 mm

<Evaluation criteria>
○: Less than 80% △: 130-80%
X: 130% or more

(2) Application failure A sample of 10 m ² obtained by Examples and Comparative Examples was prepared, the sample surface was visually observed under a fluorescent lamp, the number of small cracks was counted, and the number of small cracks was evaluated according to the following evaluation criteria. .
<Evaluation criteria>
A: The number of cracks is 1 or less.
◯: There are 2 or more and 10 or less cracks.
(Triangle | delta): A crack is 11 or more and 20 or less.
X: There are more than 20 cracks.

(3) Black Density Using an inkjet printer (“PM-A820” manufactured by Epson Corporation), black printing was performed on each of the inkjet recording sheets with black ink, and the printing density of the print sample was determined as X-rite. (X-rite Co., Ltd.) was used for measurement.

(4) Smear over time Using an inkjet printer “PM970C” manufactured by Epson Corporation, a grid-like linear pattern (line width 0.28 mm) is formed by adjoining each of the inkjet recording sheets with magenta and black ink. Printed. The print sample was inserted into a transparent PP file and stored for 3 days in an environment of temperature 35 ° C. and humidity 80% RH, and then the optical density (vis.) Of the magenta and black lattice portion was measured. By calculating this variation rate, it was used as an evaluation index for blurring over time.
Further, a blue grid pattern (line width 0.28 mm) was printed on each of the inkjet recording sheets using an inkjet printer “Pixus 850i” manufactured by Canon Inc., and the same blur evaluation was performed.
The optical density was measured using Xrite 938.
The evaluation criteria are as follows.
○: Less than 50% ○ △: 50% or more and less than 65% △: 65% or more and less than 80% ×: 80% or more

  As is clear from Table 1, all the examples satisfying the configuration of the present invention were good, and in particular, Examples 4 to 6 were excellent in all evaluation items. On the other hand, it turns out that any one evaluation item is especially inferior in the comparative example which does not have the structure of this invention.

Claims (5)

  An ink-receiving layer on a non-absorbing support, wherein at least one of the ink-receiving layers contains inorganic fine particles, polyvinyl alcohol having a saponification degree of less than 90 mol%, a cellulosic polymer, and a cationic polyurethane resin; The total content of the cellulose polymer in the ink receiving layer is 0.1 to 1.1% by mass with respect to the total mass of the inorganic fine particles. 2. The ink jet recording medium according to claim 1, wherein the total content of the cationic polyurethane resin is 3 to 7 mass% with respect to the total mass of the inorganic fine particles.   The ink jet recording medium according to claim 1 or 2, wherein a primary particle diameter of the inorganic fine particles is less than 10 nm.   A layer having two or more ink-receiving layers on the non-absorbing support, wherein the content of the cationic polyurethane resin in the layer close to the non-absorbing support is farther from the non-absorbing support than the layer The inkjet recording medium according to any one of claims 1 to 3, wherein the content of the inkjet recording medium is greater than the content of the inkjet recording medium.   The inkjet recording medium according to any one of claims 1 to 4, wherein the non-absorbent support has a 60 ° glossiness of 40% or more.