JP2009255422A - Inkjet recording medium and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording medium which has high image density and suppresses occurrence of bronzing and color change, and a manufacturing method therefor. <P>SOLUTION: Disclosed are: the inkjet recording medium containing a compound having gas-phase method silica dispersed with water-soluble aluminum salt, poly allylamine or its derivatives, and 10 pieces or more of conjugated π electrons; and a manufacturing method of the same. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an inkjet recording medium and a method for manufacturing the same.

  With the rapid development of the information technology industry in recent years, various information processing systems have been developed, and recording methods and recording apparatuses suitable for each information processing system have been put into practical use. Among these, the ink jet recording method is widely used because it can record on various recording materials, the hardware (device) is relatively inexpensive and compact, and has excellent quietness. ing. In the recording using the ink jet recording method, it has become possible to obtain a so-called photographic-like high quality recorded matter.

  In general, recording media for ink-jet recording are (1) fast-drying (high ink absorption speed), (2) proper and uniform dot diameter (no bleeding), and (3) granular (4) High roundness of dots, (5) High color density, (6) High saturation (no dullness), (7) Water resistance of image area (8) High whiteness, (9) High storage stability (no yellowing coloring or bleeding of images after long-term storage), (10) It is required to have properties such as being hard to deform and having good dimensional stability (low curl) and (11) good hard running performance.

In view of the above, in recent years, recording media in which the ink receiving layer has a porous structure have been put into practical use. According to this, it is said that it is excellent in quick-drying and high gloss is obtained.
As an invention relating to a recording medium, for the purpose of providing a recording medium excellent in aging blur and ozone resistance, inorganic fine particles are dispersed in the presence of a water-soluble polyvalent metal compound to obtain a dispersion (1). Separately, inorganic fine particles are dispersed in the presence of an organic cationic polymer to obtain a dispersion (2), and the obtained dispersions (1) and (2) are mixed, coated on a support and dried. Is disclosed (for example, see Patent Document 1).

  In addition, for the purpose of providing a recording medium having a high printing density and having excellent performance such as hue and light resistance, gas resistance and water resistance, and capable of forming an image free from bronzing. A recording medium containing a substantially colorless compound having 10 or more atoms having conjugated π electrons in one molecule is disclosed (for example, see Patent Document 2). The bronzing phenomenon refers to a phenomenon in which the applied ink does not soak into the ink absorbing layer and solidifies on the surface so that the image looks bronzed (especially the cyan image portion is reddish).

In addition, for the purpose of providing an inkjet recording medium that prevents bronzing and further prevents discoloration and fading under an oxidizing gas, an ink receiving medium having a base material and at least one layer provided on the base material is provided. An ink jet recording medium for recording with a cyan ink containing a metal complex dye, wherein the ink receiving layer has a vapor phase silica, a water-soluble compound of a polyvalent metal, and a pKa of 1.0 or more. An ink jet recording medium comprising a salt formed from an acid and an alkali metal is disclosed (for example, see Patent Document 3).
JP 2006-187883 A JP 2005-289036 A JP 2002-307818 A

  However, in the invention according to Patent Document 1, when a hydrophobic polymer is used as the organic cationic polymer, bronzing may occur, which is a problem. In the invention according to Patent Document 2 or 3, the haze after printing on the recording medium is high, and a sufficient image density is not always obtained. In the inventions according to Patent Documents 2 and 3, the color change in a short time (for example, after 1 hour) immediately after printing is large, and the quality of the photographic image quality may be deteriorated.

  The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to provide an ink jet recording medium having a high image density and capable of suppressing the occurrence of bronzing and color change, and a method for producing the same.

That is, the present invention
<1> An inkjet recording medium comprising a vapor phase silica dispersed with a water-soluble aluminum salt, polyallylamine or a derivative thereof, and a compound having 10 or more conjugated π electrons.

  <2> The inkjet recording medium according to <1>, wherein the compound having 10 or more conjugated π electrons is a compound having at least two aromatic ring groups (including aromatic heterocyclic groups).

<3> A method for producing an inkjet recording medium according to <1> or <2>,
At least a step of preparing a gas phase method silica dispersion by dispersing the gas phase method silica in the presence of a water-soluble aluminum salt, and applying an ink receiving layer coating liquid containing the gas phase method silica dispersion on a support at least. Ink jet recording medium manufacturing method.

  According to the present invention, there are provided an ink jet recording medium having a high image density and capable of suppressing the occurrence of bronzing and color change, and a method for producing the same.

Hereinafter, the ink jet recording medium of the present invention and the manufacturing method thereof will be described in detail.
The ink jet recording medium of the present invention contains a vapor phase silica dispersed with a water-soluble aluminum salt, polyallylamine or a derivative thereof, and a compound having 10 or more conjugated π electrons.

  The ink jet recording medium of the present invention comprises an ink-receiving layer on a support, and the ink-receiving layer is dispersed in a water-soluble aluminum salt, vapor-phase method silica, polyallylamine or a derivative thereof, and a compound having 10 or more conjugated π electrons It is preferable that it is an aspect containing this. The ink jet recording medium of the present invention may include other layers other than the ink receiving layer as necessary.

  In general, a porous film (ink receiving layer) formed using a coating solution containing vapor phase silica dispersed using a water-soluble aluminum salt such as polyaluminum hydroxide has a haze after printing using silica. The formed porous membrane is very low. However, since the dye mordanting power is small, the image density is low and color change is likely to occur. By applying polyallylamine or a derivative thereof to the porous film, the dye in the ink gathers in the upper layer of the porous film, and high image density and color change suppression can be achieved. However, bronzing deteriorates due to the dye in the ink gathering in the upper layer of the porous film. Therefore, a substantially colorless compound having 10 or more atoms having conjugated π electrons is provided in the porous film. As a result, it is possible to suppress the occurrence of bronzing mainly due to the association of phthalocyanine dyes.

  The polyallylamine or a derivative thereof is preferably unevenly distributed on the upper layer side of the porous film because higher image density and better color change suppression can be achieved. In this case, it is preferable that the substantially colorless compound having 10 or more atoms having conjugated π electrons is also unevenly distributed on the upper layer side of the porous film because the generation of bronzing can be effectively suppressed.

  Hereinafter, the ink jet recording medium of the present invention will be described by taking an example in which an ink receiving layer is provided on a support.

<Ink receiving layer>
The ink receiving layer according to the present invention preferably contains a gas phase method silica dispersed with a water-soluble aluminum salt, polyallylamine or a derivative thereof, and a compound having 10 or more conjugated π electrons, and if necessary, a water-soluble resin. Further, it may contain a crosslinking agent and other components.

-Compound having 10 or more conjugated pi electrons-
First, a compound having 10 or more conjugated π electrons in one molecule used in the present invention will be described. When the number of π electrons constituting a conjugated π electron system increases and the π electron system spreads, it often has absorption in the visible region. In the present invention, the compound is preferably colorless from the viewpoint of color reproduction of an image. In the present specification, the term “colorless” includes a state of being slightly colored within a range that does not affect the image. Further, although it may be a fluorescent compound, a compound having no fluorescence is preferable, and more preferably, λmax of the absorption peak on the longest wave side is 350 nm or less, more preferably 320 nm or less, and a visible light spectral region, that is, 400 A compound having a molar extinction coefficient of 10,000 or less at an arbitrary wavelength in a spectral region of ˜700 nm.
The compound of the present invention has 10 or more conjugated π electrons in one molecule. The upper limit of the number of π electrons is not particularly limited, but is preferably 80 or less, more preferably 50 or less, and particularly preferably 30 or less. Further, ten or more conjugated π electrons may form one large conjugated system, but may form two or more conjugated systems. In particular, a compound having two or more aromatic ring groups in one molecule is preferable. The aromatic ring group in this specification is an aromatic ring group in a broad sense, and forms one aromatic ring group by aromatic hydrocarbon ring group, aromatic heterocyclic group containing a hetero atom, or condensed. Any of the above groups may be used. Examples of the aromatic ring group include a benzene ring group, a naphthalene ring group, an anthracene ring group, a pyridine ring group, a pyrimidine ring group, a pyrazine ring group, and a triazine ring group.

It is particularly desirable that the compounds of the present invention have at least two solubilizing groups. Useful solubilizing groups include, but are not limited to, sulfo groups, carboxyl groups, hydroxy groups, phosphono groups, carbonamido groups, sulfonamido groups, quaternary ammonium salts and other groups apparent to those skilled in the art. . Of these, a sulfo group and a carboxyl group are preferable, and a sulfo group is most preferable.
Although the maximum number of solubilizing groups in a molecule is limited only by the number of available substituent positions, for practical purposes there are 10 identical or different solubilizing groups in the molecule. Is enough. There is no limitation on the counter cation of these solubilizing groups, and examples include alkali metal ions, ammonium ions, and organic cations (such as tetramethylammonium, guanidinium, and pyridinium cations), among which alkali metal ions and ammonium ions. In particular, lithium ion, sodium ion and ammonium ion are preferable, and lithium ion and ammonium ion are most preferable.
Specific examples of the compound include JP-A 63-55544, JP-A 3-146947, 3-149543, JP-A 2001-201831, 2002-139822, 2002-196460, The compounds described in JP-A Nos. 2002-244257, 2002-244259, 2002-296743, and 2002-296744 can be given.

Among these, compounds represented by the following general formula 1 are preferably used.
General formula 1:
A-XL- (Y-B) n
In General Formula 1, A, L, and B each independently represent an aromatic group (an aryl group and an aromatic heterocyclic group). X and Y each independently represent a divalent linking group. n represents 0 or 1. The aromatic group may be a single ring or a condensed ring. The divalent linking group represents an alkylene group, an alkenylene group, -CO-, -SOn- (n is 0, 1, 2), -NR- (R is a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group. ), -O-, and a divalent group obtained by combining these linking groups. However, the compound represented by the general formula 1 contains at least one ionic hydrophilic group selected from a sulfo group, a carboxyl group, a phenolic hydroxyl group, and a phosphono group. These ionic hydrophilic groups may be in the form of salts, and there are no restrictions on the counter cation, and examples include alkali metal ions, ammonium ions, and organic cations (each cation such as tetramethylammonium, guanidinium, and pyridinium). Among them, alkali metal ions and ammonium ions are preferable, lithium ions, sodium ions and ammonium ions are particularly preferable, and lithium ions and ammonium ions are most preferable.

  Further, the compound represented by the general formula 1 may have a substituent other than the ionic hydrophilic group, and as specific substituents, an alkyl group, an aryl group, an aralkyl group, a heterocyclic group, an alkoxy group, Aryloxy group, hydroxyl group, amino group (including anilino group and heterocyclic amino group), acyl group, acylamino group, ureido group, halogen atom, sulfamoyl group, carbamoyl group, sulfonamide group, sulfonyl group, sulfenyl group, sulfinyl Group etc. can be mentioned, These may have a substituent further. Among the compounds of general formula 1, those in which n = 1 are preferable, and those in which at least one of A, L, and B is an aromatic heterocycle are preferable. Further, those containing 2 to 4 ionic hydrophilic groups are preferred.

  It is not clear from what action mechanism the compound of the present invention suppresses bronze, but stronger π-electron interaction with dyes aggregated (associated) by π-electron interaction between dye molecules It acts as a deflocculating agent that eliminates agglomeration by acting, thus improving the bronze phenomenon. The deaggregating agent must be flat and the π-electron system greatly spread in order to enter between the aggregating dyes or to develop a strong π-electron interaction with the dyes on the surface of the dye aggregate. is important. It is also important that the deflocculating agent has sufficient solubility so that the deflocculating agent itself or a complex formed by the dye and the deflocculating agent does not precipitate. The number of necessary π electrons varies depending on the size of the ink-jet dye used, but the dye used in the ink-jet has a planar structure that greatly expands in order to increase the fixability. It is presumed that the deaggregating agent needs to be a colorless compound having a spread of more than 10 conjugated π electron systems in one molecule.

  Preferred examples of the compound used in the present invention include the aforementioned JP-A Nos. 2002-139822, 2002-196460, 2002-244257, 2002-244259, 2002-296743, and 002-296744. And compounds described in Japanese Patent Application Nos. 2002-17728 and publications. Representative compounds (deaggregating agents) are shown below.

  In the present invention, the number of atoms having conjugated π electrons in a compound refers to the number of atoms that share at least a π electron group of a conjugated bond structure that can be taken by any conjugated system. It matches the number of atoms. That is, if the number of atoms having the number of conjugated π electrons in the exemplary compounds of P-1 to P-38 is given as an example, the numbers shown in Table 1 are obtained.

The content of the compound having conjugated π electrons used in the inkjet recording medium of the present invention is preferably 0.01 to 20% by mass, and 0.1 to 10% by mass with respect to the total solid content of the ink receiving layer. More preferred. The conjugated π electron compounds may be used alone or in combination of two or more.
A preferred compound of the present invention can be easily synthesized with reference to the aforementioned JP-A No. 2002-139822.

-Gas phase method silica-
Silica fine particles are generally roughly classified into wet method particles and dry method (gas phase method) particles according to 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 “gas phase method silica” means anhydrous silica fine particles obtained by the gas phase method. In the present invention, gas phase method silica is used.

The gas phase method silica is different from hydrous silica in terms of the density of silanol groups on the surface, the presence or absence of vacancies, etc., and exhibits different properties, but is suitable for forming a three-dimensional structure with a 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 high at 5 to 8 / nm ² , and the silica fine particles tend to aggregate closely (aggregate). In the case of the method silica, the density of silanol groups on the surface of the fine particles is 2 to 3 / nm ² , so that it is sparse soft aggregation (flocculate), and as a result, it is assumed that the structure has a high porosity. Is done.

  Vapor phase silica has a particularly large specific surface area, so it has high ink absorption and retention efficiency, and its refractive index is low, so if it is dispersed to an appropriate particle size, it will provide transparency to the ink receiving layer. And high color density and good color developability can be obtained. The transparency of the ink-receiving layer is not only for applications that require transparency, such as OHP, but also for high color density and good color development gloss even when applied to recording sheets such as photo glossy paper. Is important.

  The average primary particle size of the vapor phase silica is preferably 50 nm or less, more preferably 30 nm or less, particularly preferably 20 nm or less, and most preferably 3 to 10 nm. The above-mentioned vapor phase silica is easy to adhere to each other by hydrogen bonding due to silanol groups. Therefore, when the average primary particle diameter is 50 nm or less, a structure having a large porosity can be formed, and the ink absorption characteristics can be effectively improved. Can be improved.

  Gas phase method silica may be used in combination with other fine particles. When the other fine particles and the vapor phase silica are used in combination, the content of the vapor phase silica in all the fine particles is preferably 30% by mass or more, and more preferably 50% by mass or more.

  Other fine particles used in the present invention are inorganic fine particles, but organic fine particles can also be used as long as the effects of the present invention are not impaired.

  Preferred examples of the organic fine particles include polymer fine particles obtained by emulsion polymerization, microemulsion polymerization, soap-free polymerization, seed polymerization, dispersion polymerization, suspension polymerization, and the like. Specifically, polyethylene, polypropylene, Examples include polystyrene, polyacrylate, polyamide, silicon resin, phenol resin, natural polymer powder, latex or emulsion polymer fine particles, and the like.

  Examples of the inorganic fine particles include colloidal silica, titanium dioxide, barium sulfate, calcium silicate, zeolite, kaolinite, halloysite, mica, talc, calcium carbonate, magnesium carbonate, calcium sulfate, pseudoboehmite, zinc oxide, zinc hydroxide, Examples thereof include alumina, aluminum silicate, calcium silicate, magnesium silicate, zirconium oxide, zirconium hydroxide, cerium oxide, lanthanum oxide, and yttrium oxide. The fine particles may be used as primary particles or in a state where secondary particles are formed.

As the inorganic fine particles used in the present invention, alumina fine particles, alumina hydrate, a mixture or a composite thereof are also preferable. Of these, alumina hydrate is preferable because it absorbs and fixes ink well, and pseudoboehmite (Al ₂ O ₃ .nH ₂ O) is particularly preferable. Alumina hydrates can be used in various forms, but it is preferable to use sol boehmite as a raw material because a smooth layer can be easily obtained.

About the pore structure of pseudo boehmite, the average pore radius is preferably 1 to 30 nm, and more preferably 2 to 15 nm. The pore volume is preferably 0.3 to 2.0 cc / g, more preferably 0.5 to 1.5 cc / g. Here, the pore radius and pore volume are measured by a nitrogen adsorption / desorption method, and can be measured by, for example, a gas adsorption / desorption analyzer (for example, trade name “Omni Soap 369” manufactured by Coulter). .
Among alumina fine particles, vapor-phase method alumina fine particles are preferable because of their large specific surface area. The average primary particle size of the vapor phase alumina is preferably 30 nm or less, and more preferably 20 nm or less.

  The ink receiving layer of the ink jet recording medium has a porous structure by containing vapor phase silica, thereby improving the ink absorption performance. In particular, the solid content in the ink-receiving layer of the total amount of vapor-phase process silica and other fine particles used as necessary is more than 50% by mass, more preferably more than 60% by mass. A porous structure can be formed, and an ink jet recording medium having sufficient ink absorbability can be obtained, which is preferable. Here, the solid content in the ink receiving layer of fine particles is a content calculated based on components other than water in the composition constituting the ink receiving layer.

-Water-soluble aluminum salt-
The water-soluble aluminum salt is contained when the above-mentioned gas phase method silica and other fine particles used as necessary are dispersed in a solvent such as water. A vapor phase silica dispersion is prepared by dispersing vapor phase silica or the like in the presence of a water-soluble aluminum salt.
In the present invention, “water-soluble” means that 1% by mass or more dissolves in 20 ° C. water.

  As the water-soluble aluminum salt, 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, a basic polyaluminum hydroxide compound which is an inorganic aluminum-containing cationic polymer is known and preferably used.

The basic polyaluminum hydroxide compound has a main component represented by the following general formula 2, 3 or 4, 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) nCl _6-n ] _m ·· Formula 2
[Al (OH) ₃ ] nAlCl ₃ .. Formula 3
Aln (OH) mCl (3n-m) 0 <m <3n Formula 4

  These aluminum compounds are named as basic aluminum chloride (Alphain 83) by Daimei Chemical Industry, and are treated as water treatment agents by the name of polyaluminum chloride (PAC) from Taki Chemical Co., Ltd. Asada Chemical Co., Ltd. It is marketed under the name of polyaluminum hydroxide (Paho), the name of Purachem WT from Riken Green Co., Ltd., and from other manufacturers for the same purpose. it can.

  The amount of the water-soluble aluminum salt used when dispersing the above-mentioned vapor phase silica and other fine particles used as needed in water is the total amount of the vapor phase silica and other fine particles used as necessary. It is preferable to add in the ratio of 3-80 mass% with respect to 5-60 mass%. The total concentration of the vapor phase silica in this dispersion and other fine particles used as necessary is suitably about 5 to 30% by mass, and preferably 8 to 20% by mass.

(Water-soluble resin)
In the ink jet recording medium of the present invention, the ink receiving layer preferably contains a water-soluble resin together with the compound.

Examples of the water-soluble resin include polyvinyl alcohol resins that are resins having a hydroxy group as a hydrophilic structural unit [polyvinyl alcohol (PVA), acetoacetyl-modified polyvinyl alcohol, cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol, silanol-modified. Polyvinyl alcohol, polyvinyl acetal, etc.], cellulosic resins [methyl cellulose (MC), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), carboxymethyl cellulose (CMC), hydroxypropyl cellulose (HPC), hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose, etc.] , Chitins, chitosans, starch, resins with ether linkages [polyethylene oxide (PEO), Propylene oxide (PPO), polyethylene glycol (PEG), poly ether (PVE)], and resins having carbamoyl groups [polyacrylamide (PAAM), polyvinyl pyrrolidone (PVP), polyacrylic acid hydrazide, etc.] and the like.
Moreover, the polyacrylic acid salt which has a carboxyl group as a dissociable group, maleic acid resin, alginate, gelatins, etc. can be mentioned.

Among the above, the water-soluble resin used in the present invention is at least one selected from polyvinyl alcohol resins, cellulose resins, resins having an ether bond, resins having a carbamoyl group, resins having a carboxyl group, and gelatins. In particular, polyvinyl alcohol (PVA) resin is preferable.
Examples of the polyvinyl alcohol include Japanese Patent Publication No. 4-52786, Japanese Patent Publication No. 5-67432, Japanese Patent Publication No. 7-29479, Japanese Patent No. 2537827, Japanese Patent Publication No. 7-57553, Japanese Patent No. 2502998, and Japanese Patent No. 3053231. JP-A-63-176173, JP-A-2604367, JP-A-7-276787, JP-A-9-207425, JP-A-11-58941, JP-A-2000-135858, JP-A-2001-205924, JP 2001-287444, JP 62-278080, JP 9-39373, JP 2750433, JP 2000-18801, JP 2001-213045, JP 2001-328345, JP 8 -324105, JP-A-11-348417, JP-A58-18168 JP, 10-259213, JP 2001-72711, JP 2002-103805, JP 2000-63427, JP 2002-308928, JP 2001-205919, JP 2002-264489. Etc. are mentioned.
Examples of water-soluble resins other than polyvinyl alcohol resins include compounds described in JP-A-11-165461, [0011] to [0012], JP-A-2001-205919, and JP-A-2002-264489. Examples of the compounds are also mentioned.

  These water-soluble resins may be used alone or in combination of two or more. In the present invention, the content of the water-soluble resin is preferably 9 to 40% by mass, and more preferably 12 to 33% by mass with respect to the total solid content of the ink receiving layer.

The water-soluble resin constituting the ink receiving layer may be a single material or a mixed system of a plurality of materials.
In addition, from the viewpoint of maintaining transparency, the type of water-soluble resin to be combined with gas phase method silica is important, and the water-soluble resin is preferably a polyvinyl alcohol resin, and among them, the saponification degree is 70 to 100%. The polyvinyl alcohol resin is more preferable, and a polyvinyl alcohol resin having a saponification degree of 80 to 99.5% is particularly preferable.

The polyvinyl alcohol-based resin has a hydroxyl group in its structural unit, and since this hydroxyl group and the surface silanol group of the silica fine particle form a hydrogen bond, a three-dimensional network having a secondary particle of the silica fine particle as a network chain unit. It becomes easy to form a structure. By forming this three-dimensional network structure, it is considered that a porous ink receiving layer having a high porosity and sufficient strength is formed.
In ink jet recording, the porous ink receiving layer obtained as described above can absorb ink rapidly by a capillary phenomenon, and can form dots with good roundness without ink bleeding.

  In addition, the polyvinyl alcohol resin may be used in combination with the other water-soluble resin. When the other water-soluble resin and the polyvinyl alcohol resin are used in combination, the content of the polyvinyl alcohol resin in the total water-soluble resin is preferably 50% by mass or more, and more preferably 70% by mass or more.

(Content ratio of fine particles to water-soluble resin)
The mass content ratio [PB ratio (PB ratio) of the total amount (x) of the vapor phase method silica and other fine particles (hereinafter sometimes simply referred to as “fine particles”) used in combination with the water-soluble resin (y) if necessary. x: y)] greatly affects the film structure and film strength of the ink receiving layer. That is, as the mass content ratio [PB ratio] increases, the porosity, pore volume, and surface area (per unit mass) increase, but the density and strength tend to decrease.

  In the ink receiving layer, the mass content ratio [PB ratio (x: y)] prevents a decrease in film strength and cracks during drying caused by the PB ratio being too large, and the PB ratio is When it is too small, the gap is easily blocked by the resin, and the ratio of 1.5: 1 to 10: 1 is preferable from the viewpoint of preventing the ink absorbency from being lowered due to the decrease in the void ratio.

  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 needs to have sufficient film strength. Further, when cutting into a sheet shape, the ink receiving layer needs to have sufficient film strength in order to prevent cracking or peeling of the ink receiving layer. In consideration of these cases, the mass ratio (x: y) is more preferably 5: 1 or less, while it is more preferably 2: 1 or more from the viewpoint of ensuring high-speed ink absorbency in an inkjet printer. preferable.

For example, a coating solution in which gas phase method silica fine particles having an average primary particle diameter of 20 nm or less and a water-soluble resin are completely dispersed in an aqueous solution at a mass ratio (x: y) of 2: 1 to 5: 1 is provided on the support. When the coating layer is dried, a three-dimensional network structure in which secondary particles of silica fine particles are network chains is formed, the average pore diameter is 30 nm or less, the porosity is 50 to 80%, the pore ratio A translucent porous film having a volume of 0.5 ml / g or more and a specific surface area of 100 m ² / g or more can be easily formed.

(Crosslinking agent)
The ink-receiving layer of the ink jet recording medium of the present invention preferably contains a crosslinking agent capable of crosslinking the water-soluble resin in the coating layer containing the water-soluble resin. Particularly, the fine particles and the water-soluble resin are used in combination. Furthermore, an embodiment in which the porous layer is cured by a crosslinking reaction between the crosslinking agent and the water-soluble resin is preferable.

Boron compounds are preferred for the crosslinking of the water-soluble resin, particularly polyvinyl alcohol. Examples of the boron compound include borax, boric acid, borates (for example, orthoborate, InBO ₃ , ScBO ₃ , YBO ₃ , LaBO ₃ , Mg ₃ (BO ₃ ) ₂ , Co ₃ (BO ₃ ) ₂ , two Borate (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), pentaborate (for example, KB ₅ O ₈ · 4H ₂ O, Ca ₂ B ₆ O ₁₁ · 7H ₂ O, CsB ₅ O ₅ ), etc. Of these, borax, boric acid, and borate are preferable, and boric acid is particularly preferable in that a crosslinking reaction can be promptly caused.

The following compounds other than the boron compound can also be used as the crosslinking agent for the water-soluble resin.
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 2,983611; 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-based compounds such as dioxane; titanium-containing aluminum sulfate, chromium alum, potassium alum, metal-containing compounds such as zirconyl acetate, chromium acetate, polyamine compounds such as tetraethylenepentamine, hydrazide compounds such as adipic acid dihydrazide, A low molecule or polymer containing two or more oxazoline groups can be used.
Said crosslinking agent may be used individually by 1 type, and may be used in combination of 2 or more type.

Crosslinking curing is performed by adding a crosslinking agent to a coating solution containing fine particles, a water-soluble resin or the like (hereinafter sometimes referred to as “coating solution A”) and / or the following basic solution, and (1) the coating solution At the same time as the coating layer is formed by coating the coating layer, or (2) either during the drying of the coating layer formed by coating the coating solution and before the coating layer exhibits reduced-rate drying, It is preferable to carry out by applying a basic solution having pH of 7.1 or higher (hereinafter sometimes referred to as “coating liquid B”) to the coating layer. The basic solution further preferably has a pH of 7.5 or more, particularly preferably 8 or more.
The application of the cross-linking agent is preferably performed as follows when a boron compound is taken as an example. That is, when the ink receiving layer is a layer obtained by crosslinking and curing a coating layer coated with a coating solution (coating solution A) containing fine particles, polyvinyl alcohol and a water-soluble resin, the crosslinking curing is performed by (1) the coating solution. At the same time as (2) during the dry coating of the coating layer formed by coating the coating solution, and before the coating layer exhibits a reduced rate drying, This is performed by applying a basic solution (coating solution B) having a pH of 7.1 or higher to the coating layer. The boron compound as a cross-linking agent may be contained in either the coating solution A or the coating solution B, and may be contained in both the coating solution A and the coating solution B.
1-50 mass% is preferable with respect to water-soluble resin, and, as for the usage-amount of a crosslinking agent, 5-40 mass% is more preferable.

-Polyallylamine or its derivative-
As polyallylamine or a derivative thereof used in the present invention, various known allylamine polymers and derivatives thereof can be used. Examples of such derivatives include salts of polyallylamine and acids (acids include inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid and nitric acid, methanesulfonic acid, toluenesulfonic acid, acetic acid, propionic acid, cinnamic acid, (meth) An organic acid such as acrylic acid, or a combination thereof, or a salt of only a part of allylamine), a derivative of polyallylamine by a polymer reaction, a copolymer of polyallylamine and another copolymerizable monomer Specific examples of the monomer include (meth) acrylic acid esters, styrenes, (meth) acrylamides, acrylonitrile, vinyl esters and the like.

Specific examples of polyallylamine and derivatives thereof include JP-B-62-31722, JP-B-2-14364, JP-B-63-43402, JP-A-63-43403, JP-A-63-45721, JP-A-63-29881, Japanese Patent Publication Nos. 1-26362, No. 2-56365, No. 2-57084, No. 4-41686, No. 6-2780, No. 6-45649, No. 6-15592, No. 4-68622, Patents No. 3199227, No. 3008369, JP-A-10-330427, JP-A-11-21321, JP-A-2000-281728, JP-A-2001-10636, JP-A-62-2256801, JP-A-7-173286, 7-213897, 9-235318, 9-302026, 11-21321, WO99 / 21901, WO99 / 193 No. 2, JP-A-5-140213, compounds described in JP Kohyo No. 11-506488, and the like.
The polyallylamine or a derivative thereof has a weight average molecular weight of 60000 or less, particularly 40,000 or less, from the viewpoint of preventing thickening.

In the present invention, in order to improve the water resistance and aging resistance of the formed image, the ink receiving layer may contain an organic mordant in combination with polyallylamine or a derivative thereof as necessary.
As the organic mordant, a cationic polymer (cationic mordant) is preferable, and when the mordant is present in the ink receiving layer, it interacts with a liquid ink having an anionic dye as a colorant to stabilize the colorant. It is possible to improve water resistance and aging resistance. A plurality of organic mordants and inorganic mordants may be used in combination.

  A method of adding a mordant to the coating solution A containing fine particles and a water-soluble resin, or a method of adding a mordant to the coating solution B when there is a concern of causing aggregation between the fine particles can be used.

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 quaternary ammonium base (mordant monomer), the mordant monomer and other monomers (hereinafter, What is obtained as a copolymer or condensation polymer with "non-mordant monomer") is preferred. Moreover, these polymer mordants can be used in any form of a water-soluble polymer or water-dispersible latex particles.

  Examples of the monomer (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-N -P-vinylbenzylammonium chloride, N, N-dimethyl-Nn-octyl-Np-vinylbenzylammonium chloride, N, N-dimethyl-N-benzyl-Np-vinylbenzylammonium chloride, N, N-die Ru-N-benzyl-Np-vinylbenzylammonium chloride, N, N-dimethyl-N- (4-methyl) benzyl-Np-vinylbenzylammonium chloride, N, N-dimethyl-N-phenyl-N -P-vinylbenzylammonium 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.

  Specifically, for example, monomethyl diallyl ammonium 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- (acryloylamino) ethyl Ammonium 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.
In addition, examples of copolymerizable monomers include N-vinylimidazole and N-vinyl-2-methylimidazole.

Also, diallylamine, its derivatives, salts and the like can be used. Examples of such compounds include diallylamine, diallylamine hydrochloride, diallylamine acetate, diallylamine sulfate, diallylmethylamine and salts thereof (for example, hydrochloride, acetate, sulfate, etc.), diallylethylamine and Examples of this salt (for example, hydrochloride, acetate, sulfate, etc.) and diallyldimethylammonium salt (for example, chloride, acetate ion sulfate ion, etc. as the counter anion of the salt). Since these diallylamine derivatives are inferior in polymerizability in the amine form, they are generally polymerized in a salt form and desalted as required.
In addition, a 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 also 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 show an interaction with a dye in an inkjet ink. Or the monomer which interaction is substantially small is said.
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, for example, methyl (meth) acrylate, ethyl (meth) acrylate, (meth) Propyl acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, Examples include 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, and the like.
Of these, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, and hydroxyethyl methacrylate are preferable.
The non-mordant monomers can also be used singly or in combination of two or more.

Further, as the polymer mordant, polydiallyldimethylammonium chloride, a copolymer of diallyldimethylammonium chloride and another monomer (mordant monomer, non-mordant monomer), a copolymer of diallyldimethylammonium chloride and SO ₂ , polydiallyl Cyclic amine resins such as methylamine hydrochloride and polydiallyl hydrochloride and derivatives thereof (including copolymers); polydiethylmethacryloyloxyethylamine, polytrimethylmethacryloyloxyethylammonium chloride, polydimethylbenzylmethacryloyloxyethylammonium chloride, Secondary amino, tertiary amino or quaternary ammonium salt substituted amides represented by polydimethylhydroxyethylacryloyloxyethylammonium chloride, etc. For example, alkyl (meth) acrylate polymers and copolymers with other monomers; polyamine resins represented by polyethyleneimine and derivatives thereof, polyvinylamine and derivatives thereof; polyamide-polyamine resins, polyamide epichlorohydrin resins, etc. Polyamide resins represented by cationized starch, chitosan and chitosan derivatives, etc .; dicyandiamide formalin polycondensates, dicyandiamide diethylenetriamine polycondensates and other dicyandiamide derivatives; polyamidines and polyamidine derivatives; dimethylamine epichloro Dialkylamine epichlorohydrin addition polymer represented by hydrin addition polymer, etc. and derivatives thereof; styrene polymer having quaternary ammonium salt-substituted alkyl group and other modules Copolymers of mer may be mentioned as being also preferred.

  Specific examples of the polymer mordant include JP-A Nos. 48-28325, 54-74430, 54-124726, 55-22766, 55-142339, 60-23850, and 60. -23851, 60-23852, 60-23853, 60-57836, 60-60643, 60-118834, 60-122940, 60-122941, 60-122294 Nos. 60-235134, JP-A-1-161236, U.S. Pat.Nos. 2,484,430, 2,548,564, 3,148,061, 3,309,690, 4,115,124, 4,124,386, 4,193,800, 4,273,853 No. 4282305, No. 4450224, JP-A-1-1612. No. 6, No. 10-81064, No. 10-157277, No. 10-217601, JP-A Nos. 2001-138621, 2000-212235, No. 2001-138627, JP-A No. 8-174992, and JP-B-5 -35162, 5-35163, 5-35164, 5-88846, Japanese Patent Nos. 2648847, 2616677, and the like.

The total coating amount of polyallylamine or organic mordant are used in combination according to a derivative thereof and optionally is preferably ^{0.01g / m 2 ~5g / m 2} , 0.1g / m 2 ~3g / m 2 and more preferably .

(Compound having two or more divalent or more metal atoms)
In the present invention, a compound having at least two or more divalent metal atoms in the molecule (hereinafter, this compound may be simply referred to as “metal-containing compound”) may be used. The metal atom species having a valence of 2 or more includes all metal atoms having an valence of 2 or more, and is not particularly limited. For example, magnesium, aluminum, calcium, scandium, titanium, vanadium, manganese, iron, nickel, chromium, copper, zinc, gallium, germanium, strontium, yttrium, zirconium, molybdenum, indium, barium, lanthanum, cerium, praseodymium, neodymium, Examples thereof include metal atoms such as samarium, europium, gadolinium, dysprosium, erbium, ytterbium, hafnium, tungsten, and bismuth.

As the divalent or higher valent metal atom species, those having at least two or more selected from Group II to Group IV metal elements are preferable.
Suitable examples of the group II metal elements include beryllium, magnesium, calcium, strontium, barium, and zinc.
Preferred examples of the group III metal elements include scandium, yttrium, lanthanum, boron, aluminum, gallium, indium, and thallium.
Preferable examples of the group IV metal elements include titanium, zirconium, hafnium, and thorium.

  Among the above metal elements, the divalent or higher-valent metal atomic species in the metal-containing compound is at least selected from aluminum, zirconium, titanium, lanthanoid, zinc, and magnesium from the viewpoint of the effect of improving ozone resistance and aging blur. Two or more metals are preferable, and a combination of metal atoms containing at least zirconium and at least one selected from aluminum, titanium, lanthanoid, zinc, and magnesium is more preferable.

  Further, from the viewpoint of improving the production suitability, the compound having at least two or more divalent metal atoms in the molecule is preferably a water-soluble metal-containing compound. In addition, when it is oil-soluble, it can be emulsified and dispersed or added as an organic solution, and when it is a solid compound, it can be finely divided and added as a dispersion.

  Furthermore, in order to achieve both ozone resistance and aging blur and obtain a high level of improvement effect, the metal-containing compound is preferably a composite compound formed from at least a zirconium-containing compound and an aluminum-containing compound.

  Specific examples of the zirconium-containing compound include zirconium acetylacetonate, zirconyl acetate, zirconyl sulfate, ammonium zirconium carbonate, zirconyl stearate, zirconyl octylate, zirconyl nitrate, zirconium oxychloride, zirconium hydroxychloride, zirconyl lactate, and succinate. Examples include zirconyl acid, zirconyl oxalate, basic zirconium glycinate, and any mixture thereof.

  Specific examples of the aluminum-containing compound include aluminum halide, basic aluminum chloride (polyaluminum chloride), basic aluminum sulfate, basic aluminum nitrate, basic aluminum sulfamate, basic aluminum phenol sulfonate, and these. Any mixture of and the like can be mentioned.

  Among the complex compounds containing zirconium and aluminum, the metal-containing compound is most preferably a complex compound formed using at least a basic zirconium compound and / or a basic aluminum compound.

As the basic zirconium compound that can be used for forming the metal-containing compound, a compound represented by the following general formula (I) is preferable.
Zr (OH) _x A _4-x general formula (I)
[In the above formula (I), A represents an amino acid, and x represents a number of 0 <x <4 (however, it is not necessary to be an integer). ]
Among the basic zirconium compounds represented by the general formula (I), basic zirconium-amino acid gel, zirconium hydroxide-amino acid gel, basic zirconium carbonate-amino acid gel, and a mixture thereof are preferable. These gels are preferably a reaction product of a water-soluble salt of the amino acid and a water-soluble zirconium salt, or a water-soluble salt of the amino acid and a zirconium hydroxy salt.
Moreover, as a zirconium compound, a zirconium oxy salt, a zirconium hydroxy salt, a trioxo dizirconyl hydroxy salt, and a mixture thereof are preferable.

When the basic zirconium compound is a basic zirconium carbonate gel, the basic zirconium carbonate is preferably a compound represented by the following general formula (II).
Zr (OH) _4-2x (CO ₃ ) _x general formula (II)
[In the above formula (II), x represents a number of 0 <x <2 (not necessarily an integer). ]
Among the basic zirconium carbonate gels represented by the general formula (II), those which are reaction products of sodium carbonate and zirconium oxy salt or zirconium hydroxy salt are preferable.
The general formula (I) and the general formula (II) are simplified, the compound also exists as a polymer of the general formula (I) and the general formula (II), and the ligand and / or water is Can be combined. In the general formulas (I) and (II), the OH group can be represented as an oxide (oxy group).

Acidic or cationic zirconium compounds that can be used to form metal-containing compounds are both zirconium oxy and zirconium hydroxy salts (also called zirconium and zirconyl hydroxy salts). These compounds can be represented by the following general formula (III).
_{ZrO (OH) 2-nz B} z general formula (III)
[In the above formula (III), z is about 0.9 to 2 (but not necessarily an integer), n is the valence of B, 2-nz> 0, and B is a halide. , Nitrates, sulfamates, sulfates and mixtures thereof. ]

The basic aluminum compound that can be used for forming the metal-containing compound can be represented by the following general formula (IV).
Al ₂ (OH) _6-nx B _x general formula (IV)
[In the above formula (IV), B is selected from the group consisting of halides, nitrates, sulfamates, sulfates and mixtures thereof. x represents a number of 0 <x <6 (not necessarily an integer), (6-nx) represents a number of 0 or more, and n represents a valence of B. ]
That is, the general formula (IV) represents a polymer or complex, a basic aluminum compound containing water coordination and / or a binding molecule, and a mixture thereof.
Among the basic aluminum compounds of the general formula (IV), basic aluminum chloride in which B is a chlorine atom and x is a number 2 <x <5 (it is not necessary to be an integer) in the above formula (IV). ;
Al ₂ (OH) ₂ Cl _{4 to} Al ₂ (OH) ₅ Cl
Is particularly preferred.

  In the above compound containing zirconium and aluminum, the molar ratio of zirconium to aluminum is preferably 1/100 to 100/1, more preferably 3/100 to 100/3, and particularly 5/100 to 100. Most preferred is / 5.

As a preferred embodiment of the compound having at least two or more divalent metal atoms in the molecule, there can be mentioned a complex using an organic compound in addition to the above metal atom types. As the organic compound, those having at least one oxygen atom, sulfur atom, nitrogen atom, phosphorus atom and the like having a lone pair of electrons are preferable so that they can interact with metal atom species. Examples of such organic compounds, at ^{_{least, -CO 2 -, -SO 3 -}} , -OSO 3 -, -PO 4 m- ( wherein m is an integer of 1 to 3), - _PO ^{3 2-,} - PO 2 ^_-, -O _- organic compounds having become get groups anionic group selected from. The organic compound having a group that can be an anionic group may further have a nitrogen atom.

Specific examples of the organic compound include amino acids, aliphatic carboxylic acid compounds, betaine compounds (for example, carbobetaine, sulfobetaine, phosphobetaine compounds, etc.), aromatic carboxylic acid compounds, and heterocyclic carboxylic acid compounds. An aliphatic diketone compound, an aliphatic sulfonic acid compound, an aromatic sulfonic acid compound, a heterocyclic sulfonic acid compound, an aliphatic phosphoric acid compound, an aromatic phosphoric acid compound, a heterocyclic phosphoric acid compound, an aliphatic sulfinic acid compound, Aromatic sulfinic acid compounds, heterocyclic sulfinic acid compounds, amine compounds (such as hydroxy group-containing amine compounds), amide compounds, urea compounds and the like can be mentioned.
These may be low molecular compounds or high molecular compounds which may have a substituent in the partial skeleton.

Specific examples of the compound having two or more kinds of divalent or higher metal atoms are shown below, but the invention is not limited to these compounds.
(1) Zirconium-chloro-glycine-hydroxyaluminum complex, (2) octaaluminum-zirconium-pentachloride-tricosahydride, (3) tetraaluminum-zirconium-tetrachloride-dodecahydroxide, (4) tetraaluminum - zirconium - trichloride - tridecafluoro hydroxide, (5) octa aluminum - zirconium - Okutakurorido - Aiko Sa hydroxide, (6) basic aluminum chloride _(Al 2 _(OH) 5 Cl) a mixture of zirconium lactate, (7 ) Complex of basic aluminum chloride (Al ₂ (OH) ₅ Cl) and zirconyl acetate, (8) Complex of basic aluminum chloride (Al ₂ (OH) ₅ Cl) and basic zirconium glycine, (9) Chloride Aluminum and basic jill Complex of iodonium alanine and zinc sulfate, (10) a complex of basic zirconium glycine lanthanum chloride and basic aluminum chloride _{(Al 2 (OH) 5 Cl} ), (11) a basic aluminum chloride _(Al 2 (OH) ₅ Cl), zirconium oxychloride and hydroxyethyliminodiacetic acid, (12) basic aluminum chloride (Al ₂ (OH) ₅ Cl), zirconium oxychloride and betaine, (13) myristate-methacrylato Chlorohydroxo-methanolato-isopropanolato-zirconium-aluminum, (14) 3-aminopropionato-chlorohydroxo-methanolato-zirconium-aluminum, and the like.

  In producing the ink jet recording medium of the present invention, (1) a compound having at least two or more divalent metal atoms in the molecule is formed in advance, and then the metal-containing compound is applied to the ink receiving layer coating solution. Or (2) a compound having at least two or more divalent or more metals in the target molecule at the stage of preparing the ink receiving layer coating liquid and / or mordant coating liquid. Each metal-containing compound capable of forming a (composite) (for example, a combination of a zirconium-containing compound and an aluminum-containing compound) is added simultaneously or separately, and the ink receiving layer coating liquid and / or mordant coating liquid is added. What was formed by reacting in the process of preparation may be used as it is.

  In addition, the compound having at least two kinds of metal atoms having at least two valences in the molecule is usually heated by mixing each metal-containing compound capable of forming the target metal-containing compound or as necessary. Along with this, it can be manufactured. Here, the compound of each metal may be in the form of a salt by combining with a strong acid or a weak acid, or may be in the form of a hydroxide, a halohydroxide, a complex, or the like, and formed by reacting them. The composite compound thus prepared can be contained in the ink receiving layer of the ink jet recording medium. Specific examples of such metal salts, hydroxides, halohydroxides, and complexes are listed below. That is,

  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, cupric chloride, ammonium chloride Copper (II) 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 alum, aluminum sulfite, aluminum thiosulfate, polyaluminum chloride, basic aluminum lactate, basic aluminum sulfate, basic aluminum nitrate, basic aluminum sulfamate, basic formic acid Aluminum, base Aluminum acetate, basic aluminum glycinate, aluminum nitrate nonahydrate, aluminum chloride hexahydrate, ferrous bromide, ferrous chloride, ferric chloride, ferrous sulfate, ferric sulfate, phenol Zinc sulfonate, zinc bromide, zinc chloride, zinc nitrate hexahydrate, zinc sulfate, titanium tetrachloride, tetraisopropyl titanate, titanium acetylacetonate, titanium lactate, zirconium acetylacetonate, zirconyl acetate, zirconyl sulfate, zirconium carbonate Ammonium, zirconyl stearate, zirconyl octylate, zirconyl nitrate, zirconyl lactate, zirconyl succinate, zirconyl oxalate, ammonium zirconium acetate, potassium zirconium carbonate, sodium zirconium lactate, basic zirconium glycinate, zirconium oxychloride Ni, 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, gallium nitrate, germanium nitrate, strontium nitrate, yttrium acetate, yttrium chloride, yttrium nitrate, indium nitrate, lanthanum nitrate, lanthanum chloride, lanthanum acetate, Lanthanum benzoate, cerium chloride, cerium sulfate, cerium octylate, praseodymium nitrate, neodymium nitrate, samarium nitrate, europium nitrate, gadolinium nitrate, dysprosium nitrate, erbium nitrate, indium nitrate Examples thereof include ytterbium, hafnium chloride, bismuth nitrate and the like.

  Among these, aluminum sulfate, aluminum alum, aluminum sulfite, aluminum thiosulfate, polyaluminum chloride, basic aluminum lactate, basic aluminum sulfate, basic aluminum nitrate, basic aluminum sulfamate, basic aluminum formate, basic acetic acid Aluminum-containing compounds such as aluminum, basic aluminum glycinate, aluminum nitrate nonahydrate, aluminum chloride hexahydrate; titanium-containing compounds such as titanium tetrachloride, tetraisopropyl titanate, titanium acetylacetonate, titanium lactate; and Zirconium acetylacetonate, zirconyl acetate, zirconyl sulfate, ammonium zirconium carbonate, zirconyl stearate, zirconyl octylate, zirconyl nitrate, zirconyl lactate Zirconyl succinate, zirconyl oxalate, zirconium ammonium acetate, potassium zirconium carbonate, sodium zirconium lactate, basic zirconium glycinate, zirconium oxychloride, hydroxy zirconium chloride and the like are preferred, especially basic zirconium and / or basic Aluminum salts are preferred.

In the ink receiving layer of the present invention, the content of the compound having at least two kinds of divalent or higher metal atoms in the molecule is 0.01 g / m ² in order to further improve the image blur and light resistance. is preferably to 20 g / ^{m 2,} the content is more preferably ^{0.1g / m 2 ~15g / m 2} , and most preferably an ^{0.5g / m 2 ~10g / m 2} .
If the content of the complex is less than 0.01 g / m ² , the effect of improving image blurring and light resistance may be insufficient. On the other hand, if the content exceeds 20 g / m ² , the fine particles Aggregation may easily occur when using the ink, and glossiness of the ink jet recording medium may be lowered.

(Other ingredients)
The ink jet recording medium of the present invention may further contain various known additives, such as acids, ultraviolet absorbers, antioxidants, fluorescent whitening agents, monomers, polymerization initiators, polymerization inhibitors, and anti-bleeding agents, as necessary. , Antiseptics, viscosity stabilizers, antifoaming agents, surfactants, antistatic agents, matting agents, anti-curling agents, water-proofing agents, and the like.

  In the present invention, the ink receiving layer may contain an acid. By adding an acid, the surface pH of the ink receiving layer is adjusted to 3 to 8, preferably 4 to 6. This is preferable because yellowing resistance of the white background portion is improved. The surface pH is measured by the A method (coating method) of the surface pH measurement determined by the Japan Paper Pulp Technology Association (J.TAPPI). For example, the measurement can be performed using a pH measurement set for paper “model MPC” manufactured by Kyoritsu Riken Co., Ltd. corresponding to the method A.

Specific examples of acids include formic acid, acetic acid, glycolic acid, oxalic acid, propionic acid, malonic acid, succinic acid, adipic acid, maleic acid, malic acid, tartaric acid, citric acid, benzoic acid, phthalic acid, isophthalic acid , Glutaric acid, gluconic acid, lactic acid, aspartic acid, glutamic acid, salicylic acid, salicylic acid metal salts (salts such as Zn, Al, Ca, Mg), methanesulfonic acid, itaconic acid, benzenesulfonic acid, toluenesulfonic acid, trifluoromethanesulfone Acid, styrenesulfonic acid, trifluoroacetic acid, barbituric acid, acrylic acid, methacrylic acid, cinnamic acid, 4-hydroxybenzoic acid, aminobenzoic acid, naphthalenedisulfonic acid, hydroxybenzenesulfonic acid, toluenesulfinic acid, benzenesulfinic acid, Sulfanilic acid, sulfamic acid, α-le Rucinic acid, β-resorcinic acid, γ-resorcinic acid, gallic acid, phloroglicin, sulfosalicylic acid, ascorbic acid, erythorbic acid, bisphenolic acid, hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, polyphosphoric acid, boric acid, boronic acid and the aforementioned Examples include organic and inorganic mordants that are acidic. The amount of these acids added may be determined so that the surface pH of the ink receiving layer is 3-8.
The above acids can be metal salts (eg sodium, potassium, calcium, cesium, zinc, copper, iron, aluminum, zirconium, lanthanum, yttrium, magnesium, strontium, cerium, etc.) or amine salts (eg ammonia, triethylamine, tri Butylamine, piperazine, 2-methylpiperazine, polyallylamine, etc.).

In the present invention, it is preferable that the ink receiving layer contains a preservability improving agent such as an ultraviolet absorbent, an antioxidant, or a bleeding inhibitor.
These UV absorbers, antioxidants, and anti-bleeding agents include alkylated phenol compounds (including hindered phenol compounds), alkylthiomethylphenol compounds, hydroquinone compounds, alkylated hydroquinone compounds, tocopherol compounds, and aliphatics having a thioether bond. , Aromatic and / or heterocyclic compounds, bisphenol compounds, O-, N- and S-benzyl compounds, hydroxybenzyl compounds, triazine compounds, phosphonate compounds, acylaminophenol compounds, ester compounds, amide compounds, ascorbic acid, amines Antioxidants, 2- (2-hydroxyphenyl) benzotriazole compounds, 2-hydroxybenzophenone compounds, acrylates, water-soluble or hydrophobic metal salts, organometallic compounds, metal complexes, hinders Amine compounds (including TEMPO compounds), 2- (2-hydroxyphenyl) 1,3,5-triazine compounds, metal deactivators, phosphite compounds, phosphonite compounds, hydroxyamine compounds, nitrone compounds, peroxides Scavenger, polyamide stabilizer, polyether compound, basic auxiliary stabilizer, nucleating agent, benzofuranone compound, indolinone compound, phosphine compound, polyamine compound, thiourea compound, urea compound, hydrazide compound, amidine compound, sugar compound, hydroxybenzoic acid A compound, a dihydroxybenzoic acid compound, a trihydroxybenzoic acid compound, and the like.

  Among these, alkylated phenol compounds, aliphatic, aromatic and / or heterocyclic compounds having a thioether bond, bisphenol compounds, ascorbic acid, amine-based antioxidants, water-soluble or hydrophobic metal salts, organometallic compounds , Metal complexes, hindered amine compounds, hydroxyamine compounds, polyamine compounds, thiourea compounds, hydrazide compounds, hydroxybenzoic acid compounds, dihydroxybenzoic acid compounds, trihydroxybenzoic acid compounds, and the like are preferable.

  Specific examples of the compound include JP-A No. 2002-36717, JP-A No. 2002-86904, Japanese Patent Application No. 2002-13005, JP-A No. 10-182621, JP-A No. 2001-260519, JP-B No. 4-34953, JP-B-4-34513, JP-A-11-170686, JP-B-4-34512, EP1138509, JP-A-60-67190, JP-A-7-276808, JP-A-2001-94829, JP-A-47- No. 10537, No. 58-111942, No. 58-212844, No. 59-19945, No. 59-46646, No. 59-109055, No. 63-53544, No. 36-10466, No. 42-26187. 48-30492, 48-31255, 48-41572, 48-54965, No. 50-10726, U.S. Pat. Nos. 2,719,086, 3,707,375, the 3,754,919 Patent, the 4,220,711 Patent,

  Japanese Patent Publication Nos. 45-4699, 54-5324, European Published Patent Nos. 223739, 309401, 309402, 3105301, 310552, 459416, German Published Patent No. 3435443, Kaisho 54-48535, 60-107384, 60-107383, 60-125470, 60-125471, 60-125472, 60-287485, 60-287486, 60-287487, 60-287488, 61-160287, 61-18854, 61-2111079, 62-146678, 62-146680, 62-146679, 62- No. 282885, No. 62-262047, No. 63-051174, Nos. 63-89877, 63-88380 same issue, same 66-88381 JP, same 63-113536 issue,

  63-163351, 63-203372, 63-224989, 63-251282, 63-267594, 63-182484, JP-A-1-239282, JP-A-2-262654, 2-71262, 3-121449, 4-291865, 4-291684, 5-611166, 5-119449, 5-188687, 5-188686, 5 No. 110490, No. 5-110437, No. 5-170361, No. 48-43295, No. 48-33212, U.S. Pat. Nos. 4,814,262, No. 4,980,275, and the like. .

The other components may be used alone or in combination of two or more. These other components may be added after being water-solubilized, dispersed, polymer-dispersed, emulsified or oil-dropped, or may be encapsulated in microcapsules. In the ink jet recording medium of the present invention, the addition amount of the other components is preferably 0.01 to 10 g / m ² .

  Further, the surface of the inorganic fine particles may be treated with a silane coupling agent for the purpose of improving the dispersibility of the inorganic fine particles. Examples of the silane coupling agent include an organic functional group (for example, vinyl group, amino group (primary to tertiary amino group, quaternary ammonium base), epoxy group, mercapto, in addition to the site for coupling treatment. Group, a chloro group, an alkyl group, a phenyl group, an ester group, a thioether group, etc.).

In the present invention, the ink receiving layer coating liquid preferably contains a surfactant. As the surfactant, any of cationic, anionic, nonionic, amphoteric, fluorine and silicon surfactants can be used.
Examples of the nonionic surfactant include polyoxyalkylene alkyl ethers and polyoxyalkylene alkyl phenyl ethers (for example, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene Ethylene nonylphenyl ether), oxyethylene / oxypropylene block copolymer, sorbitan fatty acid esters (for example, sorbitan monolaurate, sorbitan monooleate, sorbitan trioleate, etc.), polyoxyethylene sorbitan fatty acid esters (for example, polyoxyethylene) Sorbitan monolaurate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan Lyolate, etc.), polyoxyethylene sorbitol fatty acid esters (eg, polyoxyethylene sorbitol tetraoleate), glycerin fatty acid esters (eg, glycerol monooleate), polyoxyethylene glycerin fatty acid esters (polyoxymonostearate) Ethylene glycerol, monooleic acid polyoxyethylene glycerin, etc.), polyoxyethylene fatty acid esters (polyethylene glycol monolaurate, polyethylene glycol monooleate, etc.), polyoxyethylene alkylamine, acetylene glycols (eg, 2, 4, 7) , 9-tetramethyl-5-decyne-4,7-diol, and ethylene oxide adducts, propylene oxide adducts, and the like of the diols), and polyoxy Ruki alkylene alkyl ethers are preferable. This nonionic surfactant can be used in the 1st coating liquid and the 2nd coating liquid which are mentioned later. Moreover, the said nonionic surfactant may be used independently and may use 2 or more types together.

  Examples of the amphoteric surfactant include amino acid type, carboxyammonium betaine type, sulfoammonium betaine type, ammonium sulfate betaine type, imidazolium betaine type and the like. For example, US Pat. No. 3,843,368, JP, JP-A-59-49535, JP-A-63-236546, JP-A-5-303205, JP-A-8-262742, JP-A-10-282619, JP-A-2514194, JP-A-2759597, JP-A-2000-351269, etc. Can be used preferably. Of the amphoteric surfactants, the amino acid type, carboxyammonium betaine type, and sulfoneammonium betaine type are preferable. The amphoteric surfactants may be used alone or in combination of two or more.

Examples of the anionic surfactant include fatty acid salts (for example, sodium stearate, potassium oleate), alkyl sulfate esters (for example, sodium lauryl sulfate, triethanolamine lauryl sulfate), and sulfonates (for example, sodium dodecylbenzene sulfonate). Alkyl sulfosuccinate (for example, sodium dioctyl sulfosuccinate), alkyl diphenyl ether disulfonate, alkyl phosphate, and the like.
Examples of the cationic surfactant include alkylamine salts, quaternary ammonium salts, pyridinium salts, imidazolium salts and the like.

Examples of the fluorosurfactant include compounds derived from an intermediate having a perfluoroalkyl group using a method such as electrolytic fluorination, telomerization, or oligomerization.
Examples thereof include perfluoroalkyl sulfonates, perfluoroalkyl carboxylates, perfluoroalkyl ethylene oxide adducts, perfluoroalkyl trialkyl ammonium salts, perfluoroalkyl group-containing oligomers, and perfluoroalkyl phosphate esters.

  As the silicon-based surfactant, silicon oil modified with an organic group is preferable, and a structure in which a side chain of a siloxane structure is modified with an organic group, a structure in which both ends are modified, and a structure in which one end is modified can be taken. Examples of the organic group modification include amino modification, polyether modification, epoxy modification, carboxyl modification, carbinol modification, alkyl modification, aralkyl modification, phenol modification, and fluorine modification.

  In the present invention, the surfactant content is preferably 0.001 to 2.0%, more preferably 0.01 to 1.0%, based on the ink-receiving layer coating solution. Further, when coating is performed using two or more liquids as the ink receiving layer coating liquid, it is preferable to add a surfactant to each coating liquid.

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 an organic compound having a boiling point of 150 ° C. or higher at normal pressure, and is a water-soluble or hydrophobic compound. These may be liquid or solid at room temperature, and may be low molecules or polymers.
Specifically, aromatic carboxylic acid esters (for example, dibutyl phthalate, diphenyl phthalate, phenyl benzoate, etc.), aliphatic carboxylic acid esters (for example, dioctyl adipate, dibutyl sebacate, methyl stearate, dibutyl maleate) , Dibutyl fumarate, triethyl acetyl citrate, etc.), phosphate esters (eg, trioctyl phosphate, tricresyl phosphate, etc.), epoxies (eg, epoxidized soybean oil, epoxidized fatty acid methyl, etc.), alcohols (eg, stearyl) Alcohol, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, glycerol, diethylene glycol monobutyl ether (DEGMBE), triethylene glycol monobutyl ether, glycerol Methyl ether, 1,2,3-butanetriol, 1,2,4-butanetriol, 1,2,4-pentanetriol, 1,2,6-hexanetriol, thiodiglycol, triethanolamine, polyethylene glycol, etc. ), Vegetable oils (eg, soybean oil, sunflower oil, etc.) and higher aliphatic carboxylic acids (eg, linoleic acid, oleic acid, etc.).

(Support)
As the support of the present invention, any of a transparent support made of a transparent material such as plastic and 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 a CD-ROM or DVD-ROM, a write-once optical disk such as a CD-R or DVD-R, or a rewritable optical disk may be used as a support to provide an ink receiving layer 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 a backlight display. Examples of the material 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.
Although there is no restriction | limiting in particular as thickness of the said transparent support body, 50-200 micrometers is preferable at the point which is easy to handle.

  As the highly glossy opaque support, one having a glossiness of 40% or more on the surface on which the ink receiving layer is provided is preferable. The glossiness is a value determined according to the method described in JIS P-8142 (75-degree specular gloss test method for paper and paperboard). Specifically, the following supports are mentioned.

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, 50-300 micrometers is preferable at the point of handleability.

  The surface of the support may be subjected to corona discharge treatment, glow discharge treatment, flame treatment, ultraviolet irradiation treatment or the like in order to improve wettability and adhesion.

Next, the base paper used for the resin-coated paper will be described in detail.
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 above-mentioned wood pulp, any of LBKP, LBSP, NBKP, NBSP, LDP, NDP, LUKP, NUKP can be used, but more LBKP, NBSP, LBSP, NDP, LDP with more short fibers are used. preferable.
However, the ratio of LBSP and / or LDP is preferably 10% by mass or more and 70% by mass or less.

  The pulp is preferably a chemical pulp (sulfate pulp or sulfite pulp) with few impurities, and a pulp having a whiteness improved by bleaching 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 the pulp used for papermaking is preferably 200 to 500 ml as defined by CSF, and the fiber length after beating is a 24 mesh residual mass% and a 42 mesh residual as defined in JIS P-8207. 30 to 70% of the sum with the mass% of is preferable. In addition, it is preferable that the mass% of 4 mesh remainder is 20 mass% or less.

The basis weight of the base paper is preferably 30 to 250 g, and particularly preferably 50 to 200 g. The thickness of the base paper is preferably 40 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 is generally 0.7 to 1.2 g / m ₂ (JIS P-8118).
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 that forms the ink receiving layer is added with rutile or anatase type titanium oxide, fluorescent whitening agent, ultramarine, and polyethylene, as is widely done in photographic paper. Those having improved whiteness and hue are preferred. Here, as a titanium oxide content, about 3-20 mass% is preferable with respect to polyethylene, and 4-13 mass% is more preferable. Although the thickness of a polyethylene layer does not have limitation in particular, 10-50 micrometers is 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. Moreover, as thickness of this undercoat layer, 0.01-5 micrometers is preferable.

  Polyethylene-coated paper can be used as glossy paper, or when it is melt-extruded onto the surface of the base paper and coated, the matte surface or silky surface that can be obtained with ordinary photographic printing paper by so-called molding 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 backcoat layer include an antifoaming agent, an antifoaming agent, a dye, a fluorescent brightening agent, a preservative, and a water-proofing agent.

(Preparation of inkjet recording medium)
The ink receiving layer of the ink jet recording medium of the present invention is not particularly limited, and can be formed using a known coating method. Examples include an extrusion die coater, an air doctor coater, a bread coater, a rod coater, a knife coater, a squeeze coater, a reverse roll coater, a bar coater, and the like. The ink receiving layer may be a single layer or a multilayer structure on the support, and may further have an ink solvent absorption layer, an intermediate layer, a protective layer, and the like. Polyallylamine or a derivative thereof and a mordant used in combination as necessary may be present in the entire layer of the ink receiving layer or in the vicinity of the surface of the ink receiving layer.
A method for producing an ink jet recording medium comprises preparing a gas phase method silica dispersion by dispersing gas phase method silica in the presence of a water-soluble aluminum salt, and supporting an ink receiving layer coating liquid containing the gas phase method silica dispersion. It may include at least a step of applying on the body.
For example, a first coating liquid (coating liquid (A)) containing at least fine particles and a water-soluble resin is applied to the surface of the support, and (1) simultaneously with the coating, (2) the coating layer formed by the coating After applying a second coating solution (coating solution (B)) having a pH of 7.1 or more containing at least a basic compound in the course of drying and before the coating layer exhibits a reduced rate of drying, It is preferably formed by a method (Wet-on-Wet method) in which the coating layer provided with the second coating solution is crosslinked and cured. In this case, the gas phase method silica dispersion is contained in the coating liquid (A).
Here, the compound having at least two or more divalent metal atoms in the molecule according to the present invention is preferably contained in at least one of the coating solution (A) and the coating solution (B). In particular, it is preferably contained in the coating solution (A). In addition, a part of the compound having a divalent or higher valent metal atom that can form the metal-containing compound of the present invention is contained in the first coating liquid (the coating liquid (A)), and the remaining divalent or higher valence is added. A method of forming the metal-containing compound of the present invention by allowing a compound having a metal atom to be contained in the second coating solution (coating solution (B)) and reacting both at the time of multilayer coating described later can also be used. . Moreover, it is preferable that the crosslinking agent which can bridge | crosslink the said water-soluble resin is also contained in at least one of the said coating liquid (A) or a coating liquid (B). Providing an ink receiving layer that has been crosslinked and cured in this manner is preferable from the viewpoints of ink absorptivity and prevention of film cracking.

  In order to disperse polyallylamine or a derivative thereof and a mordant used together if necessary on the surface of the ink receiving layer (upper layer side), a coating liquid (B) is used. It is preferable to make it contain.

In the preparation of a gas phase method silica dispersion containing a gas phase method silica and a water-soluble aluminum salt, a gas phase method silica aqueous dispersion may be prepared in advance, and the water dispersion may be added to a water-soluble aluminum salt aqueous solution. Alternatively, a water-soluble aluminum salt aqueous solution may be added to the vapor phase silica aqueous dispersion, or may be mixed simultaneously. Moreover, you may add to water-soluble aluminum salt aqueous solution using the gaseous-phase-method silica of powder instead of a vapor-phase-method silica aqueous dispersion.
After mixing the vapor phase method silica and the water-soluble aluminum salt as described above, the mixture solution is finely divided using a disperser to obtain a vapor phase method silica dispersion having an average particle size of 50 to 300 nm. Obtainable. Dispersers used for obtaining the vapor phase silica dispersion include conventionally known high-speed rotary dispersers, medium agitating dispersers (ball mill, sand mill, etc.), ultrasonic dispersers, colloid mill dispersers, high pressure dispersers, and the like. However, an ultrasonic disperser, a stirring disperser, a colloid mill disperser, or a high pressure disperser is preferable from the viewpoint of efficiently dispersing the formed fine particles. .

In the present invention, an ink receiving layer coating liquid (coating liquid (A)) containing at least fine particles (for example, vapor-phase process silica) and a water-soluble resin (for example, polyvinyl alcohol) is prepared, for example, as follows. can do.
That is, gas phase method silica and a water-soluble aluminum salt are added to water (for example, 10 to 20% by mass of silica fine particles in water), and a high-pressure disperser of an opposing collision type (for example, Ultima manufactured by Sugino Machine Co., Ltd.). For example, a gas phase method silica dispersion is obtained by dispersing under a pressure condition of 130 MPa (preferably 100 to 160 MPa) using a crosslinking agent (boron compound), polyvinyl alcohol. (PVA) An aqueous solution (for example, PVA having a mass of about 1/3 of the above-mentioned vapor phase method silica) can be added and prepared. 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 coating this on 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.

  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, so that surface smoothness, glossiness, It is possible to improve 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.

In the case of ink jet recording, the thickness of the ink receiving layer needs to have an absorption capacity sufficient to absorb all of the droplets, and therefore needs to be determined in relation to the porosity in the layer.
For example, if the ink amount is 8 nL / mm ² and the porosity is 60%, a film having a layer thickness of about 15 μm or more is required.
Considering this point, in the case of ink jet recording, the layer thickness of the ink receiving layer is preferably 10 to 50 μm.

Further, the pore diameter of the ink receiving layer is preferably 0.005 to 0.030 μm, more preferably 0.01 to 0.025 μm in terms of median diameter.
The porosity and pore median diameter can be measured using a mercury porosimeter (trade name “Pore Sizer 9320-PC2” manufactured by Shimadzu Corporation).

In addition, the ink receiving layer is preferably excellent in transparency, as a guide, the haze value when the ink receiving layer is formed on a transparent film support is preferably 30% or less, More preferably, it is 20% or less.
The haze value can be measured using a haze meter (HGM-2DP: Suga Test Instruments Co., Ltd.).

  A polymer fine particle dispersion may be added to a constituent layer (for example, an ink receiving layer or a back layer) of the ink jet recording medium of the present invention. This polymer fine particle dispersion is used for the purpose of improving film properties such as dimensional stabilization, curling prevention, adhesion prevention, and film cracking prevention. The polymer fine particle dispersion is described in JP-A-62-245258 and JP-A-10-228076. If a polymer fine particle dispersion having a low glass transition temperature (40 ° C. or lower) is added to the layer containing the mordant, cracking and curling of the layer can be prevented. Further, even when a polymer fine particle dispersion having a high glass transition temperature is added to the back layer, curling can be prevented.

  Ink jet recording media of the present invention are disclosed in JP-A-10-81064, JP-A-10-119423, JP-A-10-157277, JP-A-10-217601, JP-A-11-348409, JP-A-2001-138621, 2000. No. 43401, No. 2000-21235, No. 2000-309157, No. 2001-96897, No. 2001-138627, JP-A-11-91242, No. 8-2087, No. 8-2090, No. 8- It can also be produced by the methods described in Japanese Patent Nos. 2091 and 8-2093.

  An undercoat layer may be provided on the support for the purpose of improving the adhesion between the ink receiving layer and the support and appropriately adjusting the electric resistance value.

  The ink receiving layer may be provided only on one side of the support, or may be provided on both sides of the support for the purpose of preventing deformation such as curling. When the ink receiving layer is provided only on one side of the support, the anti-reflection film may be provided on the opposite side surface or both sides for the purpose of increasing light transmission. .

  In addition, by applying boric acid or a boron compound to the surface of the support on the side where the ink receiving layer is provided, and forming an ink receiving layer thereon, the glossiness and surface smoothness of the ink receiving layer can be improved. In addition, it is possible to suppress aging blurring of an image after printing in a high temperature and high humidity environment.

(Inkjet recording method)
In the ink jet recording method of the present invention, the ink jet recording method is not limited, and a known method, for example, a charge control method in which ink is ejected using electrostatic attraction, or a drop-on-demand method using vibration pressure of a piezo element. Method (pressure pulse method), acoustic ink method that converts electrical signals into acoustic beams, irradiates ink, and ejects ink using radiation pressure, and forms bubbles by heating ink and uses generated pressure A thermal ink jet method is used. Inkjet recording methods use a method of ejecting a large number of low-density inks called photo inks in a small volume, a method of improving image quality using a plurality of inks having substantially the same hue and different concentrations, and colorless and transparent inks. The method is included.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples. In the examples, “parts” and “%” represent “parts by mass” and “% by mass” unless otherwise specified.

[Example 1]
<Preparation of polyolefin resin-coated paper support>
A 1: 1 mixture of hardwood bleached kraft pulp (LBKP) and softwood bleached sulfite pulp (NBSP) was beaten to 300 ml with Canadian Standard Freeness to prepare a pulp slurry. As a sizing agent, alkylketene dimer is 0.5% to pulp, polyacrylamide is 1.0% to pulp, and cationized starch is 2.0% to pulp. Polyamide epichlorohydrin resin is 0 to pulp. 0.5% was added and diluted with water to make a 1% slurry. This slurry was made with a long paper machine to a basis weight of 170 g / m ² , dried and conditioned to obtain a polyolefin resin-coated paper base paper. A polyethylene resin composition in which 10% anatase-type titanium is uniformly dispersed with respect to a resin of 100% low density polyethylene having a density of 0.918 g / cm ³ is melted at 320 ° C. at a temperature of 200 m / min. Extrusion coating was carried out to a thickness of 35 μm, and extrusion coating was performed using a cooling roll having a finely roughened surface. On the other side, a blend resin composition of 70 parts of a high density polyethylene resin having a density of 0.962 g / cm ³ and 30 parts of a low density polyethylene resin having a density of 0.918 was similarly melted at 320 ° C. to a thickness of 30 μm. Extrusion-coating was performed, and extrusion coating was performed using a cooling roll having a roughened surface.

The polyolefin resin-coated paper surface was subjected to high-frequency corona discharge treatment, and then an undercoat layer having the following composition was applied and dried so that the gelatin content was 50 mg / m ² to prepare a support.

<Underlayer>
Lime-processed gelatin 100 parts Sulfosuccinic acid-2-ethylhexyl ester salt 2 parts Chrome alum 10 parts

<Creation of vapor phase silica dispersion>
Vapor phase silica fine particles having the following composition, ion exchange water, and alpha-in 83 are mixed and subjected to ultrasonic dispersion, and then the dispersion is heated to 30 ° C. and held for 8 hours to obtain a vapor phase silica dispersion. Prepared. The vapor phase silica dispersion had a viscosity of 43 mPa · s and an average particle size of 0.109 μm.
Here, the average particle diameter was measured using LA-920 manufactured by HORIBA.

<Composition of vapor phase silica dispersion>
Gas phase method silica 299.6 parts (AEROSIL300SF75, Nippon Aerosil Co., Ltd.)
Ion-exchanged water 1400 parts Alpha-in 83 (40.0% aqueous solution)
(Dispersant, manufactured by Daimei Chemical Industry Co., Ltd.) 300 parts

(Preparation of ink receiving layer coating liquid A)
(A) Gas phase method silica dispersion having the following composition, (b) polyvinyl alcohol, (c) boric acid, (d) polyoxyethylene lauryl ether, and (e) ion-exchanged water are mixed to form an ink receiving layer. Liquid A was prepared.
The mass ratio between the silica fine particles and the water-soluble resin (PB ratio was 4.0: 1, and the pH of the ink receiving layer coating liquid A was 3.5, indicating acidity.

<Composition of Ink Receiving Layer Coating Liquid A>
(A) Gas phase method silica dispersion 59.3 parts (b) Polyvinyl alcohol (water-soluble resin) 8% aqueous solution 27.8 parts ("PVA235" manufactured by Kuraray Co., Ltd., saponification degree 88%,
Degree of polymerization 3500)
(C) Boric acid (crosslinking agent) 0.4 parts (d) Polyoxyethylene lauryl ether (surfactant) 1.2 parts (“Emulgen 109P” (10% aqueous solution) manufactured by Kao Corporation, HLB value 13. 6)
(E) 33.0 parts of ion exchange water

(Preparation of recording medium)
The ink receiving layer coating liquid A is applied to the surface on which the undercoat layer of the support is provided using an extrusion die coater at a coating amount of 200 ml / m ² (coating process), and then heated with a hot air dryer. It was dried at 80 ° C. (wind speed 3-8 m / sec) until the solid content concentration of the coating layer reached 20%. This coating layer exhibited a constant rate of drying during this period. Immediately after that, it was immersed in a mordant solution B having the following composition for 30 seconds to deposit 20 g / m ² on the coating layer (step of applying a mordant solution), and further dried at 80 ° C. for 10 minutes (drying step). ).
Thereby, an ink jet recording medium provided with an ink receiving layer having a dry film thickness of 32 μm was produced.

<Composition of mordant coating liquid B>
(A) Boric acid (crosslinking agent) 0.65 parts (b) Polyallylamine “PAA-03” 20% aqueous solution 12.5 parts (mordant, manufactured by Nittobo Co., Ltd.)
(C) Ion-exchanged water 69 parts (d) Ammonium carbonate (surface pH adjuster) 5 parts (e) Polyoxyethylene lauryl ether (surfactant) 10 parts ("Emulgen 109P" manufactured by Kao Corporation, 2% Aqueous solution,
HLB value 13.6)
(F) 1% of the exemplified compound P-1 (based on solids)

[Evaluation]
The obtained inkjet recording medium was evaluated for bronzing, printing density, color change (ΔE measurement) and post-printing haze according to the following methods. The obtained results are shown in Table 3.
<Bronzing>
A 100% cyan solid portion was printed with a commercially available inkjet printer (Seiko Epson Corporation PM-A820), and the presence or absence of bronzing was visually evaluated based on the following criteria.
A: The reflected fluorescent light does not turn red at all, but maintains whiteness.
○: The reflected fluorescent light turns slightly red.
Δ: The reflected fluorescent light turns red.
×: All reflected fluorescent lights turn red.

<Print density>
Black solid printing was performed using an Seiko Epson inkjet printer PM-A820. The image density of the black (K) solid print portion was measured using Gretag Spectrolino SPM-50 under the conditions of a viewing angle of 2 °, a light source D50, and no filter.

<ΔE measurement>
Using an A820 printer manufactured by Seiko Epson, gray solid printing was performed on an inkjet recording medium. At that time, the gradation of the image data was adjusted so that the gray density was 1.7. Immediately after printing and 24 hours later, the hue of the gray portion was measured, and the magnitude of the color change was evaluated using the color difference (ΔE). For the measurement, a spectrophotometer (Spectrolino, manufactured by Gretag Macbeth Co.) was used, L * a * b was measured under the conditions of the light source F8 and the viewing angle of 2 degrees, and the color difference (ΔE) was calculated from the difference. From the color difference value, ranking was performed according to the following criteria.
A: ΔE <2 Color change is hardly recognized B: 2 ≦ ΔE <4 Color change is noticeable but not so noticeable C: 4 ≦ ΔE <7 Color change is quite noticeable D: 7 ≦ ΔE Color change is quite large Level

<Haze after printing>
Haze measurement was performed using a haze meter (HGM-2DP type manufactured by Suga Test Instruments). After printing, the haze measurement is performed by first filling the empty ink tank with the ink solvent shown in Table 2 and discharging the ink solvent under the same conditions as the ink discharge conditions for black solid printing using the Seiko Epson inkjet printer A820. did. After printing, the sample was allowed to stand under conditions of 23 ° C. and 50% RH for 24 hours, and then haze was measured.

  In Table 2, TEGmBE represents triethylene glycol monobutyl ether. Each unit is “part”.

[Example 2]
An inkjet recording medium was prepared in the same manner as in Example 1 except that the exemplified compound P-1 was changed to the exemplified compound P-29, and evaluated in the same manner as in Example 1. The obtained results are shown in Table 3.

[Example 3]
An inkjet recording medium was prepared in the same manner as in Example 1 except that the exemplified compound P-1 was changed to the exemplified compound P-35, and evaluated in the same manner as in Example 1. The obtained results are shown in Table 3.

[Example 4]
An inkjet recording medium was prepared in the same manner as in Example 1 except that the exemplified compound P-1 was changed to the exemplified compound P-36, and evaluated in the same manner as in Example 1. The obtained results are shown in Table 3.

[Comparative Example 1]
An ink jet recording medium was prepared in the same manner as in Example 1 except that the exemplified compound P-1 was changed to benzotriazole-5-carboxylic acid, and evaluated in the same manner as in Example 1. The obtained results are shown in Table 3.

[Comparative Example 2]
An ink jet recording medium was prepared in the same manner as in Example 1 except that the exemplified compound P-1 was not added, and evaluated in the same manner as in Example 1. The obtained results are shown in Table 3.

[Comparative Example 3]
<Creation of vapor phase silica dispersion> In the same manner as in Example 1 except that 300 parts of alpha-in 83 (40.0% aqueous solution) was changed to 26.2 parts of Charol DC902P (polydiallyldimethylammonium chloride). An ink jet recording medium was prepared and evaluated in the same manner as in Example 1. The obtained results are shown in Table 3.

[Comparative Example 4]
In <Composition of Mordant Coating Liquid B>, an ink jet recording medium was prepared in the same manner as in Example 1 except that polyallylamine “PAA-03” was not used, and evaluated in the same manner as in Example 1. The obtained results are shown in Table 3.

Claims (3)

  An ink jet recording medium comprising a vapor phase silica dispersed with a water-soluble aluminum salt, polyallylamine or a derivative thereof, and a compound having 10 or more conjugated π electrons.   The inkjet recording medium according to claim 1, wherein the compound having 10 or more conjugated π electrons is a compound having at least two aromatic ring groups (including aromatic heterocyclic groups). A method for producing an ink jet recording medium according to claim 1 or 2,
A step of preparing a gas phase method silica dispersion by dispersing the gas phase method silica in the presence of a water-soluble aluminum salt, and applying at least an ink receiving layer coating liquid containing the gas phase method silica dispersion on a support; A method for producing an inkjet recording medium.