JP2007008030A - Method for manufacturing inkjet recording medium and inkjet recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an inkjet recording medium capable of an inkjet recording medium excellent in a coated face state, and to provide the inkjet recording medium manufactured by the manufacturing method. <P>SOLUTION: In the method for manufacturing the inkjet recording medium providing an ink receiving layer on a substrate, the method for manufacturing the inkjet recording medium comprises an ink receiving layer forming process in which the ink receiving layer is formed by laminating and coating a coating liquid (1) mixing a finely divided particle dispersion in which at least one kind of finely divided particle is dispersed with at least one kind of a cationic polymer and a binder, and a coating liquid (2) capable of increasing viscosity of the coating liquid (1) on the substrate, and the coating liquid (1) and the coating liquid (2) have a pH of 8 or lower. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an ink jet recording medium, and more particularly to a method for manufacturing an ink jet recording medium capable of manufacturing an ink jet recording medium having a good surface shape.

  In recent years, with the rapid development of the information technology (IT) industry, various information processing systems have been developed, and a recording method and a recording apparatus suitable for each information processing system have been developed and put into practical use. Among such recording methods, the inkjet recording method is advantageous in that it can be recorded on various recording materials, the hardware (device) is relatively inexpensive, compact, and excellent in low noise. It has been widely used not only in offices but also in so-called home use.

In addition, with the recent increase in resolution of inkjet printers, it is also possible to obtain so-called photographic-like high-quality recorded materials, and along with the further development of hardware (device), various recording sheets for inkjet recording are also available. Improvements have been made.
The characteristics required for a recording sheet for ink jet recording are generally (1) fast drying (fast ink absorption speed), and (2) proper and uniform ink dot diameter (bleeding). (3) Good graininess, (4) High roundness of dots, (5) High color density, (6) High saturation (no dullness) ), (7) The light resistance and water resistance of the print portion are good, (8) The whiteness of the recording sheet is high, (9) The recording sheet has good storage stability (yellowing coloration during long-term storage) (10) hard to deform, good dimensional stability (curl is sufficiently small), (11) good running performance of hardware, Etc. Furthermore, in the use of photo glossy paper used for the purpose of obtaining so-called photographic-like high-quality recorded matter, in addition to the above characteristics, glossiness, surface smoothness, texture of photographic paper similar to silver salt photography, etc. Required.

  In recent years, an ink jet recording medium having a porous structure in an ink receiving layer has been developed and put into practical use for the purpose of improving the various characteristics described above. Such an ink jet recording medium has a porous structure, so that it has excellent ink receptivity (fast drying property) and high glossiness.

  For example, there has been proposed an ink jet recording medium containing fine inorganic pigment particles and a water-soluble resin and having an ink receiving layer having a high porosity on a support (for example, see Patent Documents 1 and 2). ). These recording sheets, particularly ink jet recording media provided with an ink receiving layer having a porous structure using silica as inorganic pigment fine particles, are excellent in ink absorptivity due to the structure, and can form high-resolution images. It has ink receptive performance and can exhibit high gloss.

  In addition, a silica dispersion of a coating solution using boric acid as a crosslinking agent is used (for example, see Patent Document 3). In the coating solution containing the silica dispersion and boric acid, there is a demand for increasing the concentration of the coating solution from the viewpoint of productivity, for example, by increasing the coating surface state. However, if a crosslinking agent is present in the coating solution, the initial viscosity of the coating solution tends to increase, and the viscosity further increases with time, resulting in a problem that the coated surface of the ink receiving layer is deteriorated. It was. Thus, there is a problem that it is difficult to increase the concentration of the coating liquid.

On the other hand, an inkjet recording sheet manufacturing method is disclosed in which one or more coating liquids are applied by simultaneous extrusion in order to coat the coating liquid on a support (see, for example, Patent Document 4). However, even such a manufacturing method has not yet solved the problems such as the above-described increase in the viscosity of the coating liquid and difficulty in increasing the concentration due to the crosslinking agent.

JP 10-119423 A Japanese Patent Laid-Open No. 10-217601 JP 61-199979 A JP 2001-96904 A

  According to the present invention, it is an object to provide an ink jet recording medium manufacturing method capable of providing an ink jet recording medium having an excellent coated surface, and an ink jet recording medium manufactured by the manufacturing method. And

  Means of the present invention for solving the above-mentioned problems are as follows. That is,

<1> A method for producing an ink jet recording medium comprising an ink receiving layer forming step of forming an ink receiving layer on a support,
In the ink receiving layer forming step, the coating liquid (1) in which at least one kind of fine particles are dispersed in at least one kind of cationic polymer and a binder are mixed, and the coating liquid (1) is thickened. A coating liquid (2) capable of being coated on the support, and the coating liquid (1) and the coating liquid (2) have an pH of 8 or less. This is a method for manufacturing a recording medium.

  <2> The method for producing an inkjet recording medium according to <1>, wherein the coating liquid (2) contains a crosslinking agent capable of crosslinking the binder.

  <3> The method for producing an inkjet recording medium according to <2>, wherein the crosslinking agent is a boron-containing compound.

  <4> The method for producing an inkjet recording medium according to <1>, wherein the coating liquid (2) contains a water-soluble polyvalent metal salt.

  <5> The inkjet according to <1> to <4>, wherein the fine particles are at least one selected from organic fine particles, silica fine particles, colloidal silica, alumina fine particles, and pseudoboehmite type aluminum hydroxide fine particles. This is a method for manufacturing a recording medium.

  <6> The coating solution (2) containing a crosslinking agent, the coating solution (1), and the coating solution (2) containing a water-soluble polyvalent metal salt are laminated in this order from the support side. The method for producing an ink jet recording medium according to <1>, wherein a multilayer coating is applied.

  <7> The method for producing an ink jet recording medium according to <1> to <6>, wherein the fine particles are vapor phase silica having an average primary particle diameter of 30 nm or less.

  <8> In the ink receiving layer forming step, a latex containing at least a cation-modified polymer is used, and an average particle size of the cation-modified polymer is 0.1 μm or less. <1> to <7> A method for producing an inkjet recording medium.

  <9> The method for producing an inkjet recording medium according to <8>, wherein the latex containing the cation-modified polymer is an aqueous dispersion of a cationic urethane resin.

  <10> In the coating step, the coating solution (1) and the coating solution (2) are applied in multiple layers to form a coating layer, or simultaneously, or the coating solution (1) and the coating solution (2) are stacked. At any time during the drying of the coating layer formed by coating and before the coating layer exhibits a reduced rate of drying, a basic solution having a pH of 7.1 or more is applied to the coating layer, The method for producing an inkjet recording medium according to <1> to <9>, wherein the ink receiving layer is formed by crosslinking and curing.

  <11> An inkjet recording medium obtained by the method for manufacturing an inkjet recording medium according to <1> to <10>.

  <12> 30% by mass or more of the total amount of the water-soluble polyvalent metal salt contained in the ink receiving layer is present in a range of 5 μm from the surface of the ink receiving layer. It is a medium.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the ink jet recording medium which can provide the inkjet recording medium excellent in the coated surface shape, and the ink jet recording medium manufactured by this manufacturing method can be provided. .

<< Method for producing inkjet recording medium >>
The method for producing an ink jet recording medium of the present invention is a method for producing an ink jet recording medium including an ink receptive layer forming step of forming an ink receptive layer on a support,
In the ink receiving layer forming step, the coating liquid (1) in which at least one kind of fine particles are dispersed in at least one kind of cationic polymer and a binder are mixed, and the coating liquid (1) is thickened. And a coating step of applying a multilayer coating on the support, wherein the coating solution (1) and the coating solution (2) have a pH of 8 or less.
According to the method for producing an ink jet recording medium of the present invention (hereinafter sometimes referred to as “the production method of the present invention”), the coating liquid (1) and the coating in the coating step included in the ink receiving layer forming step. Applying multiple layers of coating liquid (2) (hereinafter sometimes referred to as “thickening promoting liquid”) capable of thickening coating liquid (1) which is a coating liquid different from liquid (1). Thus, it is possible to prevent the coating liquid (1) from being thickened due to the presence of a cross-linking agent, a water-soluble polyvalent metal salt, and the like and the coating surface state from being lowered.
As described above, according to the production method of the present invention, a substance capable of thickening the coating liquid (1) such as fine particles, a binder, a cross-linking agent and a water-soluble polyvalent metal salt on the support, and necessary Accordingly, it is possible to produce an ink jet recording medium having an ink receiving layer containing a mordant or the like and having an excellent coated surface of the ink receiving layer.
The coating liquids (1) and (2) have a pH of 8 or less. In the present invention, the ink receiving layer is preferably formed on the support by the wet on wet method described later.
Hereinafter, the production method of the present invention will be described.

  First, the components contained in the coating liquids (1) and (2) in the present invention will be described. The coating liquid (1) contains a fine particle dispersion in which at least one kind of fine particles are dispersed with at least one kind of cationic polymer and a binder. The coating liquid (2) includes, for example, a substance capable of thickening the coating liquid (1) (hereinafter, sometimes referred to as “thickening substance”). The coating liquids (1) and (2) in the present invention can contain a solvent, a surfactant and the like as necessary in addition to the above-described essential components.

  The pH of the coating liquids (1) and (2) is 8 or less, more preferably 7 or less, and particularly preferably 4.5 or less. When the pH exceeds 8, the amount of the coated surface may become large, and a good glossy surface cannot be obtained. Further, the lower limit of the pH of the coating liquids (1) and (2) is not particularly limited, but from the viewpoint of preventing cracking, the pH is preferably 2.0 or more, and preferably pH 3.0 or more. Further preferred.

In a conventional method for producing an ink jet recording medium, a cross-linking agent such as boric acid is used in advance mixed with a mixture of fine particles and a binder. However, when the crosslinking agent, the fine particles and the binder are mixed, there is a problem that the initial viscosity of the coating liquid tends to be high, and the viscosity further increases with time, resulting in a poor coating surface of the ink receiving layer. .
In the production method of the present invention, for example, a coating liquid (2) containing a substance such as boric acid that thickens the coating liquid (1) containing fine particles and a binder is applied to a coating liquid different from the coating liquid (1). The above-mentioned problems can be solved by adding them to the film and applying them in multiple layers.

  When the coating liquid (2) contains a water-soluble polyvalent metal salt such as polyaluminum chloride as a substance for thickening the coating liquid (1), the water-soluble polyvalent metal salt is added to the ink receiving layer. It can be present on the surface side. Thereby, the ozone resistance and the bleed resistance of the ink receiving layer can be improved.

  The coating liquids (1) and (2) in the present invention may each be a plurality of types having different components. That is, an ink receiving layer can be formed by applying a single coating liquid (1) and two coating liquids (2) in multiple layers. That is, a coating liquid (1) containing a fine particle dispersion and a binder, a first coating liquid (2) containing a boron-containing compound (crosslinking agent), and a second coating liquid containing a water-soluble polyvalent metal salt ( When 2) is used, the first coating liquid (2), the coating liquid (1), and the second coating liquid (2) are laminated from the support side in this order from the support side. can do.

<Coating liquid (1)>
(Fine particle dispersion)
The coating liquid (1) in the present invention contains a fine particle dispersion. The fine particle dispersion is a dispersion in which at least one kind of fine particles is dispersed with at least one kind of cationic polymer.

-Fine particles-
The fine particles include organic fine particles, silica fine particles, colloidal silica, alumina fine particles, titanium dioxide, barium sulfate, calcium silicate, zeolite, kaolinite, halloysite, mica, talc, calcium carbonate, magnesium carbonate, calcium sulfate, boehmite, pseudoboehmite. Type aluminum hydroxide fine particles. Among these, organic fine particles, silica fine particles, colloidal silica, alumina fine particles, and pseudo boehmite type aluminum hydroxide fine particles are preferable, and silica fine particles, alumina fine particles, and pseudo boehmite type aluminum hydroxide fine particles are more preferable. Among these, silica fine particles are preferable, and particularly when vapor phase silica having a primary particle diameter of 30 nm is used, remarkable effects such as a good porous structure can be obtained. These fine particles may be used alone or in combination of several kinds.

  Examples of the organic fine particles include fine particles such as polystyrene and styrene butadiene latex, and polystyrene fine particles are preferable. The organic fine particles are preferably cationized on the surface. The glass transition temperature (Tg) of the organic fine particles is not particularly limited, but when used alone, the Tg is preferably 40 ° C. or higher, more preferably 80 ° C. or higher.

  Since the silica fine particles have a particularly large specific surface area, the ink absorption and retention efficiency is high, and the refractive index is low. Therefore, if the dispersion is performed to an appropriate fine particle diameter, transparency can be imparted to the ink receiving layer. There is an advantage that high color density and good color developability can be obtained. Thus, the fact that the receiving layer is transparent means that not only for applications that require transparency, such as OHP, but also when applied to recording sheets such as photo glossy paper, high color density and good color developability and This is important from the viewpoint of obtaining glossiness.

  In particular, silica fine particles have silanol groups on their surfaces, and the particles are likely to adhere to each other by hydrogen bonding of the silanol groups, and because of the adhesion effect between the particles via the silanol groups and the water-soluble resin, Similarly, when the average primary particle size is 30 nm or less, the ink receiving layer has a high porosity and a highly transparent structure can be formed, and the ink absorption characteristics can be effectively improved. The average primary particle diameter of the silica fine particles is preferably 15 nm or less.

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

Vapor phase method silica is different from the hydrous silica in 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 high porosity. The reason for this is not clear, but in the case of hydrous silica, the density of silanol groups on the surface of the fine particles is as high as 5 to 8 / nm ^2, and the silica fine particles tend to agglomerate closely (aggregate). In the case of the method silica, the density of silanol groups on the surface of the fine particles is as small as ² to 3 / nm ² , so that it becomes sparse soft agglomeration (flocculate), and as a result, it is estimated that the structure has a high porosity. The
In the present invention, vapor phase silica fine particles (anhydrous silica) obtained by the dry method are preferred, and silica fine particles having a density of 2 to 3 silanol groups / nm ² on the fine particle surface are more preferred.

  The content of the fine particles in the present invention is preferably 5 to 70% by mass, more preferably 5 to 40% by mass with respect to the total amount of the coating liquid (1). Most preferably, it is 5-15 mass%. When the ratio of the fine particles in the coating solution is large, the viscosity of the coating solution increases, and it may be difficult to obtain a good coated surface state. Moreover, when the ratio of the fine particles in the coating solution is too small, the fluidity of the coating solution is increased, and it may be difficult to obtain a good coated surface shape.

-Cationic polymer-
The cationic polymer contained in the fine particle dispersion is a polymer having a primary to tertiary amino group or a quaternary ammonium base as a cationic group, and a latex containing a cationically modified polymer described later. In addition, the same cationic group-containing polymer and cationic mordant used in this can be used.

(binder)
The coating liquid (1) in the present invention contains a binder.
Examples of the binder include resins having a hydroxyl group as a hydrophilic structural unit, such as polyvinyl alcohol (PVA), cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol, silanol-modified polyvinyl alcohol, polyvinyl acetal, cellulose resin [methyl cellulose ( MC), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), carboxymethyl cellulose (CMC), etc.], chitins, chitosans, starch; polyethylene oxide (PEO), polypropylene oxide (resin having a hydrophilic ether bond) PPO), polyethylene glycol (PEG), polyvinyl ether (PVE); a polyacrylic resin that has a hydrophilic amide group or amide bond Bromide (PAAM), polyvinyl pyrrolidone (PVP) and the like. Moreover, polyacrylic acid salt, maleic acid resin, alginic acid salt, gelatins etc. which have a carboxyl group as a dissociative group can be mentioned.
Among the above, polyvinyl alcohol (PVA) is particularly preferable.

The saponification degree of the polyvinyl alcohol is preferably 75 to 95, and more preferably 77 to 90. When the saponification degree is in the range of 75 to 95, the black density can be improved by combining with the cationic polymer contained in the fine particle dispersant.
The polymerization degree of the polyvinyl alcohol is preferably 1400 to 5000, more preferably 2300 to 5000, and particularly preferably 3600 to 5000. When the polymerization degree is in the range of 1400 to 5000, the viscosity can be sufficiently reduced and sufficient film strength can be obtained. In addition, conventionally, when polyvinyl alcohol having a degree of polymerization exceeding 3500 is used, the viscosity of the coating solution cannot be reduced to a viscosity suitable for coating, and an ink receiving layer having an excellent coated surface is formed. Was very difficult.
However, according to the production method of the present invention, even when the polyvinyl alcohol has a degree of polymerization of more than 3500 and less than or equal to 5000, the viscosity can be lowered and a good coated surface can be obtained. Furthermore, according to the production method of the present invention, by using polyvinyl alcohol having a high degree of polymerization, it is possible to improve the coated surface and increase the strength of the ink receiving layer.

  Examples of the polyvinyl alcohol include cation-modified PVA, anion-modified PVA, silanol-modified PVA and other polyvinyl alcohol derivatives in addition to polyvinyl alcohol (PVA). Polyvinyl alcohol may be used alone or in combination of two or more.

The PVA has a hydroxyl group in its structural unit, and this hydroxyl group and the silanol group on the surface of the silica fine particle form a hydrogen bond, and it is easy to form a three-dimensional network structure in which the secondary particle of the silica fine particle is a chain unit. To do. By forming such a three-dimensional network structure, it is considered that an ink receiving layer having a porous structure with a high porosity can be formed.
The porous ink receiving layer obtained as described above can absorb ink rapidly by capillary action, and can form dots with good roundness without ink bleeding.

  The content of the binder in the coating liquid (1) in the present invention is such that a decrease in film strength and cracking at the time of drying due to an excess of the content are prevented, and an excess of the content causes the voids to be resin. 9 to 40% by mass with respect to the fine particles contained in the coating liquid (1) is preferable from the viewpoint of preventing the ink absorbability from being reduced due to the decrease in the porosity. -33 mass% is more preferable.

(Content ratio of fine particles to binder)
The content ratio of the fine particles (preferably silica fine particles; x) and the binder (y) [PB ratio (x / y), the mass of the inorganic pigment fine particles relative to 1 part by mass of the binder] has a great influence on the film structure of the ink receiving layer. give. That is, as the PB ratio increases, the porosity, pore volume, and surface area (per unit mass) increase. Specifically, as the PB ratio (x / y), the decrease in film strength and cracking during drying caused by the PB ratio being too large are prevented, and the PB ratio is too small. From the viewpoint of preventing the gap from being easily blocked by the resin and preventing the ink absorbability from being lowered due to a decrease in the void ratio, 1.5 / 1 to 10/1 is preferable.

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

For example, a coating solution in which anhydrous silica fine particles having an average primary particle size of 20 nm or less and a water-soluble resin are completely dispersed in an aqueous solution with a PB ratio (x / y) of 2/1 to 5/1 is coated on a support. When the coating layer is dried, a three-dimensional network structure in which the secondary particles of silica fine particles are chain units is formed, the average pore diameter is 30 nm or less, the porosity is 50% to 80%, and the pore specific volume is 0. A translucent porous film having a surface area of 5 ml / g or more and a specific surface area of 100 m ² / g or more can be easily formed.

<Coating liquid (2)>
The “coating liquid (2) capable of thickening the coating liquid (1)” (thickening promoting liquid) means that the viscosity of the coating liquid (1) is 1 by mixing with the coating liquid (1). A coating solution that can be raised 5 times or more. For example, the coating liquid (1) containing vapor-phase process silica rapidly increases in viscosity when the liquid pH becomes 4.5 or more. Accordingly, a basic coating solution or the like that raises the pH of the solution can be used as the thickening promoting solution. The thickening promoting liquid also includes a coating liquid containing a substance (thickening substance) that changes the dispersion stable state by adsorbing to a pigment and thickens the system. Examples of such thickening substances include water-soluble polyvalent metal salts and some cationic polymers.
In order to confirm the thickening behavior of the coating liquid (1), a predetermined amount of thickening promoting liquid (coating liquid (2)) is added to the coating liquid (1) and mixed to determine the viscosity after 24 hours. The viscosity can be confirmed by measuring and comparing the viscosity of the coating liquid (1) before and after the addition of the coating liquid (2). The measurement temperature is 40 ° C. from the viewpoint of data stability. In addition, the degree of thickening is preferably 2 times or more, more preferably 10 times or more, and in order to obtain a good coated surface by simultaneous multi-layering. The thickening after 10 minutes of mixing the coating liquid (1) and the coating liquid (2) is within 1.5 times, and more preferably 1.5 times or more thereafter.

(Thickener)
Examples of the thickening substance include a crosslinking agent and a water-soluble polyvalent metal salt. Hereinafter, the thickening substance will be described using these as examples.

-Crosslinking agent-
In the present invention, it is preferable that the ink receiving layer containing the fine particles and the binder is a porous layer further containing a crosslinking agent capable of crosslinking the binder and cured by a crosslinking reaction of the binder by the crosslinking agent. The crosslinking agent is a compound that aggregates and thickens by reaction with the fine particles when added to the coating liquid (1).

As the cross-linking agent, a suitable one may be selected as appropriate in relation to the binder contained in the coating liquid (1). Among them, a boron-containing compound is preferable in that the cross-linking reaction is rapid. For example, borax, boric acid, borate (eg, _{orthoborate, InBO 3, ScBO 3, YBO} 3, LaBO 3, Mg 3 (BO 3) 2, Co 3 (BO 3) 2, two borates (e.g., Mg ₂ B ₂ O ₅ , Co ₂ B ₂ O ₅ ), metaborates (eg, LiBO ₂ , Ca (BO ₂ ) ₂ , NaBO ₂ , KBO ₂ ), tetraborate (eg, Na ₂ B ₄ O ₇ .10H ₂ O) And pentaborate (for example, KB ₅ O ₈ .4H ₂ O, Ca ₂ B ₆ O ₁₁ .7H ₂ O, CsB ₅ O ₅ ), etc. Among them, a crosslinking reaction can be promptly caused. In this respect, borax, boric acid, and borate are preferable, and boric acid is particularly preferable. It is most preferable to use this in combination with polyvinyl alcohol as a binder.

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

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

In the present invention, the cross-linking agent is preferably included in the coating liquid (2) when forming the ink-receiving layer, but when the coating liquid (2) contains other thickening substances, You may include in a coating liquid (1) in the range which does not impair the effect of this invention. Moreover, it can also be included in both coating liquid (1) and (2) in the range which does not impair the effect of this invention.
As content of the said crosslinking agent contained in the coating liquid (2) in this invention, it is 5-40 with respect to the binder contained in a coating liquid (1) from a viewpoint of the improvement of the printing density of an image, and a glossiness. % By mass is preferable, and 10 to 30% by mass is more preferable.

  When the coating liquid (2) in the present invention contains a crosslinking agent such as a boron-containing compound, the coating liquid (2) containing the crosslinking agent is laminated on the support side with respect to the coating liquid (1). It is preferable to apply multiple layers. Thus, by applying both coating solutions in multiple layers, a glossy surface with high gloss and few cracks can be obtained.

-Water-soluble polyvalent metal salt-
In the present invention, in order to improve the water resistance and aging resistance of the formed image, a water-soluble metal compound can be contained in the coating liquid (2) in order to impart a mordant to the ink receiving layer. The water-soluble polyvalent metal salt is a substance that, when added to the coating liquid (1), thickens by interaction with pigments (fine particles) and a water-soluble binder.

Examples of the water-soluble polyvalent metal salt compound include water-soluble salts of metals selected from calcium, barium, manganese, copper, cobalt, nickel, aluminum, iron, zinc, zirconium, chromium, magnesium, tungsten, and molybdenum. It is done.
Specifically, calcium acetate, calcium chloride, calcium formate, calcium sulfate, barium acetate, barium sulfate, barium phosphate, manganese chloride, manganese acetate, manganese formate dihydrate, manganese ammonium sulfate hexahydrate, second chloride Copper, ammonium chloride (II) chloride dihydrate, copper sulfate, cobalt chloride, cobalt thiocyanate, cobalt sulfate, nickel sulfate hexahydrate, nickel chloride hexahydrate, nickel acetate tetrahydrate, nickel ammonium sulfate Hexahydrate, nickel amidosulfate tetrahydrate, aluminum sulfate, aluminum sulfite, aluminum thiosulfate, polyaluminum chloride, aluminum nitrate nonahydrate, aluminum chloride hexahydrate, ferrous bromide, ferrous chloride Iron, ferric chloride, ferrous sulfate, ferric sulfate, zinc bromide, zinc chloride, zinc nitrate hexahydrate , Zinc sulfate, zirconium acetate, zirconium chloride, zirconium chloride octahydrate, hydroxy zirconium chloride, chromium acetate, chromium sulfate, magnesium sulfate, magnesium chloride hexahydrate, magnesium citrate nonahydrate, sodium phosphotungstate Sodium tungsten citrate, 12 tungstophosphoric acid n hydrate, 12 tungstosilicic acid 26 hydrate, molybdenum chloride, 12 molybdophosphoric acid n hydrate, and the like.

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

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

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

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

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

  Although the water-soluble polyvalent metal salt compound can be used alone, it is preferable to use two or more kinds in combination.

In the present invention, the water-soluble polyvalent metal salt is preferably contained in the coating liquid (2) when forming the ink receiving layer, but other thickening substances and the like are contained in the coating liquid (2). In such a case, it may be included in the coating liquid (1) as long as the effects of the present invention are not impaired. Moreover, it can also be included in both coating liquid (1) and (2) in the range which does not impair the effect of this invention.
The content of the water-soluble polyvalent metal salt contained in the coating liquid (2) in the present invention is from the viewpoint of improving the image printing density and glossiness with respect to the fine particles contained in the coating liquid (1). 0.05 to 10% by mass is preferable, and 0.1 to 7% by mass is more preferable.

  When the water-soluble polyvalent metal salt is contained in the coating liquid (2) in the present invention, the coating liquid (2) containing the water-soluble polyvalent metal salt is more on the surface side (supporting) than the coating liquid (1). It is preferable to apply multiple layers so as to be laminated on the side opposite to the side where the body is provided. In this way, by applying both coating liquids in multiple layers, 30% by mass or more of the total amount of the water-soluble polyvalent metal salt contained in the ink receiving layer is in the range of 5 μm from the surface of the ink receiving layer. Can be formed.

  By allowing the water-soluble polyvalent metal salt to exist at least in the upper layer of the ink receiving layer, an interaction works with the liquid ink for ink jet having an anionic dye as a coloring material, and the coloring material is stabilized. Thus, water resistance and aging resistance can be further improved.

(Latex containing cation-modified polymer)
In the ink-receiving layer forming step in the production method of the present invention, latex containing a cation-modified polymer (hereinafter sometimes simply referred to as “latex”) can be used. “Latex” here means a colloidal dispersion having a particle diameter of 0.001 μm to 0.1 μm or an emulsion-like substance of 0.1 μm to 10 μm.
Specifically, the latex can be used by adding to at least one of the coating solution (1) or (2) [first coating solution] and the basic solution [second coating solution] as described later. From the viewpoint of being sufficiently mixed with the fine particles and binder in the first coating liquid and effectively preventing bleeding over time, it is contained in the first coating liquid (coating liquid (1) and / or coating liquid (2)). The embodiment to be made is preferable. At this time, it is not always necessary to include all of the latex in the first coating liquid, and it is also effective to include at least a part of the latex in the second coating liquid, thereby effectively preventing bleeding over time. be able to.

  The “cation-modified polymer” refers to a polymer compound that can form a naturally stable emulsified dispersion in an aqueous dispersion medium without using an emulsifier or a surfactant, or even with a small amount of addition. means. Quantitatively, the “cation-modified polymer” refers to a polymer substance having a stable emulsifying dispersibility at a concentration of 0.5% by mass or more with respect to the aqueous dispersion medium at room temperature of 25 ° C. The concentration is preferably 1% by mass or more, more preferably 3% by mass or more.

  When a cation-modified polymer such as cationized polyurethane is mixed with a water-soluble polyvalent metal salt (particularly, basic polyaluminum chloride), the coating solution may be thickened. Therefore, when using cationized polyurethane or the like, the production method of the present invention is particularly effective.

  More specifically, the “cation-modified polymer” is, for example, a polyaddition or polycondensation polymer compound of a monomer having a cationic group such as a primary to tertiary amino group or a quaternary ammonium group. Is mentioned. The “latex containing a cation-modified polymer” can also be used as a cationic polymer contained in the coating solution (1).

  Examples of the vinyl polymerization polymer effective as a cation-modified polymer contained in the latex include polymers obtained by polymerizing the following vinyl monomers. That is, acrylic acid esters and methacrylic acid esters (the ester group is an alkyl group or aryl group which may have a substituent, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n- Butyl group, sec-butyl group, tert-butyl group, hexyl group, 2-ethylhexyl group, tert-octyl group, 2-chloroethyl group, cyanoethyl group, 2-acetoxyethyl group, tetrahydrofurfuryl group, 5-hydroxypentyl group Cyclohexyl group, benzyl group, hydroxyethyl group, 3-methoxybutyl group, 2- (2-methoxyethoxy) ethyl group, 2,2,2-tetrafluoroethyl group, 1H, 1H, 2H, 2H-perfluorodecyl Group, phenyl group, 2,4,5-tetramethylphenyl group, 4-chlorophenyl group, etc.);

  Vinyl esters, specifically, aliphatic carboxylic acid vinyl esters which may have a substituent (for example, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl caproate, vinyl Chloroacetate, etc.), optionally substituted aromatic carboxylic acid vinyl ester (for example, vinyl benzoate, vinyl 4-methylbenzoate, vinyl salicylate, etc.);

  Acrylamides, specifically, acrylamide, N-monosubstituted acrylamide, N-disubstituted acrylamide (the substituent is an alkyl group, aryl group, silyl group which may have a substituent, such as a methyl group, n-propyl group, isopropyl group, n-butyl group, tert-butyl group, tert-octyl group, cyclohexyl group, benzyl group, hydroxymethyl group, alkoxymethyl group, phenyl group, 2,4,5-tetramethylphenyl group , 4-chlorophenyl group, trimethylsilyl, etc.);

  Methacrylamide, specifically, methacrylamide, N-monosubstituted methacrylamide, N-disubstituted methacrylamide (substituents are optionally substituted alkyl, aryl, silyl groups, for example , Methyl group, n-propyl group, isopropyl group, n-butyl group, tert-butyl group, tert-octyl group, cyclohexyl group, benzyl group, hydroxymethyl group, alkoxymethyl group, phenyl group, 2,4,5- Tetramethylphenyl group, 4-chlorophenyl group, trimethylsilyl, etc.);

  Olefins (for example, ethylene, propylene, 1-pentene, vinyl chloride, vinylidene chloride, isoprene, chloroprene, butadiene, etc.), styrenes (for example, styrene, methylstyrene, isopropylstyrene, methoxystyrene, acetoxystyrene, chlorostyrene, etc.) Vinyl ethers (for example, methyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, methoxyethyl vinyl ether, etc.);

  Other vinyl monomers include crotonic acid ester, itaconic acid ester, maleic acid diester, fumaric acid diester, methyl vinyl ketone, phenyl vinyl ketone, methoxyethyl vinyl ketone, N-vinyl oxazolidone, N-vinyl pyrrolidone, methylene malon nitrile, diphenyl Examples include 2-acryloyloxyethyl phosphate, diphenyl-2-methacryloyloxyethyl phosphate, dibutyl-2-acryloyloxyethyl phosphate, dioctyl-2-methacryloyloxyethyl phosphate, and the like.

  Examples of the monomer having a cationic group include monomers having a tertiary amino group such as dialkylaminoethyl methacrylate and dialkylaminoethyl acrylate.

Examples of the polyurethane applicable as a cation-modified polymer contained in the latex include, for example, polyurethanes synthesized by a polyaddition reaction using various combinations of the following diol compounds and diisocyanate compounds.
Specific examples of the diol compound include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 2,2 -Dimethyl-1,3-propanediol, 1,2-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 2,4-pentanediol, 3,3-dimethyl-1,2-butanediol, 2 -Ethyl-2-methyl-1,3-propanediol, 1,2-hexanediol, 1,5-hexanediol, 1,6-hexanediol, 2,5-hexanediol, 2-methyl-2,4-pentanediol 2,2-diethyl-1,3-propanediol, 2,4-dimethyl-2,4-pentanediol, 1,7-heptane All, 2-methyl-2-propyl-1,3-propanediol, 2,5-dimethyl-2,5-hexanediol, 2-ethyl-1,3-hexanediol, 1,2-octanediol, 1, 8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-cyclohexanedimethanol, hydroquinone, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol (average molecular weight = 200,300,400,600,1000,1500,4000), polypropylene glycol (average molecular weight = 200,400,1000), polyester polyol, 4,4′-dihydroxy-diphenyl-2,2-propane, 4,4 ′ -Dihydroxyphenyls Luhon etc. are mentioned.

  Examples of the diisocyanate compound include methylene diisocyanate, ethylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, 1,4-cyclohexane diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,3-xylylene diisocyanate, 1, 5-naphthalene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 3,3′-dimethyl-4,4′-diphenylmethane diisocyanate, 3,3′-dimethylbiphenylene diisocyanate, 4,4′-biphenylene diisocyanate, dicyclohexylmethane diisocyanate , Methylenebis (4-cyclohexylisocyanate) and the like.

The cationically modified polymer contained in the latex is preferably a urethane resin having a cationic group such as a tertiary amine and a quaternary ammonium salt.
A polyurethane containing a cationic group can be obtained, for example, by using a product obtained by introducing a cationic group into a diol as described above during the synthesis of polyurethane. In the case of a quaternary ammonium salt, a polyurethane containing a tertiary amino group may be quaternized with a quaternizing agent.

  The diol compound and diisocyanate compound that can be used for the synthesis of the polyurethane may be used alone or for various purposes (for example, preparation of glass transition temperature (Tg) of polymer and improvement of solubility). Depending on the compatibility with the binder, improvement of the stability of the dispersion, etc., two or more of them can be used in any proportion.

Furthermore, examples of the polyester applicable to the cation-modified polymer contained in the latex include polyesters synthesized by polycondensation reaction using various combinations of the following diol compounds and dicarboxylic acid compounds. .
Examples of the dicarboxylic acid compound include oxalic acid, malonic acid, succinic acid, glutaric acid, dimethylmalonic acid, adipic acid, pimelic acid, α, α-dimethylsuccinic acid, acetone dicarboxylic acid, sebacic acid, 1,9-nonanedicarboxylic acid. Acid, fumaric acid, maleic acid, itaconic acid, citraconic acid, phthalic acid, isophthalic acid, terephthalic acid, 2-butyl terephthalic acid, tetrachloroterephthalic acid, acetylenedicarboxylic acid, poly (ethylene terephthalate) dicarboxylic acid, 1,2- Examples include cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, ω-poly (ethylene oxide) dicarboxylic acid, and p-xylylene dicarboxylic acid.

  When performing the polycondensation reaction with the diol compound, the dicarboxylic acid compound may be used in the form of an alkyl ester of dicarboxylic acid (for example, dimethyl ester) and an acid chloride of dicarboxylic acid, or maleic anhydride, anhydrous It may be used in the form of an acid anhydride such as succinic acid and phthalic anhydride.

  As the diol compound, the same compounds as the diols exemplified in the polyurethane can be used.

  The cationic group-containing polyester can be obtained by synthesis using a dicarboxylic acid compound having a cationic group such as a primary, secondary, tertiary amine, or quaternary ammonium salt.

  The diol compounds, dicarboxylic acids, and hydroxycarboxylic acid ester compounds used in the synthesis of the polyester may be used alone or in various ways (for example, preparation of the glass transition temperature (Tg) of the polymer). Or two or more of them may be mixed and used in an arbitrary ratio depending on the solubility, compatibility with the dye, and stability of the dispersion.

The content of the cationic group in the cation-modified polymer contained in the latex is preferably 0.1 to 5 mmol / g, and more preferably 0.2 to 3 mmol / g. In addition, when there is too little content of the said cationic group, the dispersion stability of a polymer will become small, and when too large, compatibility with a binder will fall.
Further, the cationic group is preferably such that the quaternary ammonium group is 50 mol% or more of the total cationic group, from the viewpoint of light resistance and bleeding suppression effect, more preferably 80 mol% or more, and 95 mol%. Is most preferred.

  As the cation-modified polymer contained in the latex, a polymer having a cationic group such as a tertiary amino group or a quaternary ammonium base is preferable, and a urethane resin having a cationic group as described above is most preferable, Similarly, the latex containing the cation-modified polymer is preferably an aqueous dispersion of a cationic urethane resin.

  The glass transition temperature of the cation-modified polymer contained in the latex such as cationized polyurethane is not particularly limited, but those having a glass transition temperature of 40 ° C. or higher are preferable from the viewpoint of improving the strength of the ink receiving layer. Conversely, if a latex containing a cation-modified polymer having a glass transition temperature of 40 ° C. or lower is used, the brittleness improving effect can be obtained. Furthermore, the latex containing a cation-modified polymer such as cationized polyurethane is preferably formed into a film by application of heat or the like, not in a particle state, after coating and drying. Thus, by forming a film of the aqueous dispersion, the haze of the ink receiving layer can be lowered, and a high color density can be obtained. The average particle size of the aqueous dispersion is preferably 0.3 μm or less, and more preferably 0.1 μm or less, from the viewpoint of preventing cracking and obtaining a high Dm.

  The mass average molecular weight (Mw) of the cation-modified polymer contained in the latex used in the present invention is usually preferably from 1,000 to 1,000,000, more preferably from 300,000 to 800,000. When the molecular weight is in the range of 1,000 to 1,000,000, a stable aqueous dispersion is easily obtained, the solubility is not lowered and the liquid viscosity is not increased, and the average particle size of the aqueous dispersion is reduced. In particular, it is easy to control to 0.05 μm or less.

  The content of the cation-modified polymer in the latex is preferably determined to be 0.1 to 30% by mass of the total solid content of the ink receiving layer, and is 0.3 to 20% by mass. Is more preferable, and 0.5 to 15% by mass is particularly preferable. When the content is in the range of 0.1% by mass to 30% by mass, the effect of improving bleeding over time can be sufficiently exerted, and the ratio of the fine particles and the binder component is reduced, so that the ink absorbability to high-quality recording paper is reduced. Will not drop.

Next, a method for preparing the latex will be described.
The cation-modified polymer is mixed with an aqueous solvent, an additive is mixed as necessary, and the mixture is finely divided using a disperser, so that the average particle size is 0.05 μm or less. An aqueous dispersion can be obtained. Dispersers used for obtaining the aqueous dispersion include conventionally known high-speed rotary dispersers, medium stirring dispersers (ball mill, sand mill, bead mill, etc.), ultrasonic dispersers, colloid mill dispersers, high pressure dispersers, and the like. Various dispersers can be used. From the viewpoint of efficiently dispersing the formed fine particles, a medium stirring type disperser, a colloid mill disperser, or a high pressure disperser is preferable.

  The high-pressure disperser (homogenizer) is described in detail in US Pat. No. 4,533,254, JP-A-6-47264, etc., but as a commercially available apparatus, a Gorin homogenizer (APV GAULIN) is used. INC.), A microfluidizer (MICROFLUIDEX INC.), An optimizer (Sugino Machine Co., Ltd.) and the like can be used. In recent years, a high-pressure homogenizer having a mechanism for atomizing in an ultrahigh-pressure jet stream as described in US Pat. No. 5,720,551 is particularly effective for emulsification dispersion of the present invention. DeBEE2000 (BEE INTERNIONAL LTD.) Is an example of an emulsifying apparatus using this ultra-high pressure jet stream.

  As the aqueous solvent in the dispersion step, water, an organic solvent, or a mixed solvent thereof can be used. Examples of the organic solvent that can be used for the dispersion include alcohols such as methanol, ethanol, n-propanol, i-propanol, and methoxypropanol, ketones such as acetone and methyl ethyl ketone, tetrahydrofuran, acetonitrile, ethyl acetate, and toluene. It is done.

  The cation-modified polymer contained in the latex can itself become a naturally stable emulsified dispersion, but a small amount of a dispersing agent (surface active agent) is used to make the emulsified dispersion more quickly or more stable. Agent). Surfactants used for such purposes include, for example, fatty acid salts, alkyl sulfate esters, alkylbenzene sulfonates, alkyl naphthalene sulfonates, dialkyl sulfosuccinates, alkyl phosphate esters, naphthalene sulfonate formalin condensates. , Anionic surfactants such as polyoxyethylene alkyl sulfates, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene Nonionic surfactants such as alkylamines, glycerin fatty acid esters and oxyethyleneoxypropylene block copolymers are preferred. Further, SURFYNOLS (Air Products & Chemicals), which is an acetylene-based polyoxyethylene oxide surfactant, is also preferably used. An amine oxide type amphoteric surfactant such as N, N-dimethyl-N-alkylamine oxide is also preferred. Further, pages (37) to (38) of JP-A-59-157,636, Research Disclosure No. Those listed as surfactants described in 308119 (1989) can also be used.

  In order to stabilize immediately after emulsification, a water-soluble polymer can be added in combination with the surfactant. As the water-soluble polymer, polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene oxide, polyacrylic acid, polyacrylamide or a copolymer thereof is preferably used. It is also preferable to use natural water-soluble polymers such as polysaccharides, casein, and gelatin.

  When the cation-modified polymer is dispersed in an aqueous medium by the emulsion dispersion method, it is particularly important to control the particle size. In order to increase color purity and color density when an image is formed by inkjet, it is necessary to reduce the average particle size of the cation-modified polymer contained in the latex. Specifically, in the ink receiving layer of the present invention, the volume average particle size of the cation-modified polymer needs to be 0.05 μm or less, and the average particle size is 0.04 μm or less. More preferably, it is 0.03 μm or less.

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

The material that can be used for the transparent support is preferably a material that is transparent and can withstand radiant heat when used in an OHP or a backlight display. Examples of such materials include polyesters such as polyethylene terephthalate (PET); polysulfone, polyphenylene oxide, polyimide, polycarbonate, polyamide, and the like. Of these, polyesters are preferable, and polyethylene terephthalate is particularly preferable.
Although there is no restriction | limiting in particular as thickness of the said transparent support body, 50-200 micrometers is preferable at the point of the ease of handling.

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

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

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

  The freeness of 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. The 4 mesh residue is preferably 20% by 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 in polyethylene, as is widely done in photographic paper, and the opacity is increased. 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 matte or silky surface that can be obtained with ordinary photographic printing paper by applying a so-called molding process when polyethylene is melt-extruded and coated on the base paper surface. Can also be used.

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

Examples of the aqueous binder used in the back coat 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.

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

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

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

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

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

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

  These anti-fading agents may be used alone or in combination of two or more. The anti-fading agent may be water-solubilized, dispersed, emulsified, or contained in microcapsules. As the addition amount of the antifading agent, 0.01 to 10% by mass is preferably added to the coating liquid (1) or (2).

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

As content in the said coating liquid (1) or (2) of the said high boiling point organic solvent, 0.05-1 mass% is preferable, Most preferably, it is 0.1-0.6 mass%.
Further, for the purpose of enhancing the dispersibility of the inorganic pigment fine particles, various inorganic salts and pH adjusting agents may contain acids, alkalis and the like.
Further, for the purpose of suppressing surface frictional charge and peeling charge, the metal oxide fine particles having electronic conductivity may contain various matting agents for the purpose of reducing the surface frictional characteristics.

<Ink-receiving layer forming step>
In the production method of the present invention, in the coating step of the ink receiving layer forming step, a coating film is formed by applying at least one coating liquid (1) and (2) on the support, respectively, The ink-receiving layer can be formed by applying a crosslinking effect to the coating film as necessary. The ink receiving layer forming step may include steps other than the coating step.
In the production method of the present invention, in the ink-receiving layer forming step, the coating liquid (1) and the coating liquid (2) are applied in multiple layers to form a coating layer, or simultaneously with the coating liquid (1) and A basic solution having a pH of 7.1 or higher at any time during the drying of the coating layer formed by applying the coating solution (2) in multiple layers and before the coating layer exhibits a reduced rate of drying. Is preferably formed by a method of forming the ink receiving layer by crosslinking and curing the coating layer (hereinafter sometimes referred to as “Wet on Wet method”).

  With respect to the coating solutions (1) and (2) (hereinafter sometimes referred to as “first coating solution”) coated in multiple layers in this way, simultaneously with the multilayer coating or during the drying of the coating layer formed by the multilayer coating The ink receiving layer that is crosslinked and cured by applying a basic solution (second coating solution) to any one of the coating layers before the coating layer exhibits a reduced rate of drying has an ink absorptivity, prevention of film cracking, etc. In addition to the above advantages, it is particularly preferable for improving the appearance of repelling failure and the like.

In the present invention, the coating liquids (1) and (2) as the first coating liquid can be prepared, for example, as follows.
That is, the coating liquid (1) is prepared by adding silica fine particles having an average primary particle size of 20 nm or less to water and a cationic polymer (for example, 10 to 20% by mass), and a high-speed rotating wet colloid mill (for example, M Technique). (Cleamix Co., Ltd.)), for example, after being dispersed for 20 minutes (preferably 10 to 30 minutes) under the condition of high speed rotation of 10000 rpm (preferably 5000 to 20000 rpm), It can be prepared by adding a polyvinyl alcohol aqueous solution (for example, PVA having a mass of about 1/3 of silica) and further dispersing under the same rotation conditions as described above. The obtained coating liquid is a uniform sol, and this is coated simultaneously with the coating liquid (2) on the support by the following coating method to obtain a porous ink receiving layer having a three-dimensional network structure. Can do.
Further, the coating liquid (2) is prepared by adding a boron-containing compound (for example, 0.5 to 20% by mass of silica) and / or a water-soluble polyvalent metal salt and dispersing under the same conditions as described above. Can do.
If necessary, a pH adjuster, a dispersant, a surfactant, an antifoaming agent, an antistatic agent, and the like can be further added to the coating liquids (1) and (2).

  As the dispersing machine used for the dispersion, various conventionally known dispersing machines such as a high-speed rotary dispersing machine, a medium stirring type dispersing machine (ball mill, sand mill, etc.), an ultrasonic dispersing machine, a colloid mill dispersing machine, and a high-pressure dispersing machine are used. However, in order to efficiently disperse the generated fine particles, a medium stirring type disperser, a colloid mill disperser or a high pressure disperser is preferable.

  The simultaneous application (multilayer application) of the coating liquids (1) and (2) can be performed, for example, by a coating method using an extrusion die coater or a curtain flow coater. After the simultaneous coating, the formed coating layer is dried. In this case, the drying is generally performed by heating the coating layer at a temperature of 40 to 150 ° C. for 0.5 to 10 minutes, preferably at a temperature of 40 It is carried out by heating at -100 ° C for 0.5-5 minutes.

  When the simultaneous coating (multilayer coating) is performed by, for example, an extrusion die coater, two types of coating liquid discharged at the same time are close to the discharge port of the extrusion die coater, that is, before moving onto the support. A multilayer is formed, and in that state, the multilayer is applied on the support.

  A second coating solution (basic solution) is applied to the coating layer after or simultaneously with the application of the first coating solution (coating solutions (1) and (2)). You may provide before the coating layer after application | coating comes to show reduction-rate drying. That is, after the application liquid for the ink receiving layer is applied, it is preferably manufactured by introducing a basic solution while the applied layer exhibits constant rate drying. The second coating liquid may contain a mordant. The mordant will be described later.

  Here, “before the coating layer comes to show reduced drying” usually refers to a process for several minutes immediately after the coating of the coating liquid for the ink-receiving layer. This shows a phenomenon of “constant rate drying” in which the content of the solvent (dispersion medium) of the ink decreases in proportion to time. The time indicating “constant rate drying” is described in, for example, “Chemical Engineering Handbook” (pages 707 to 712, published by Maruzen Co., Ltd., October 25, 1980).

  As described above, after the application of the first coating liquid, the coating layer is dried until the coating layer exhibits reduced-rate drying. This drying is generally performed at a temperature of 50 to 180 ° C. for 0.5 to 10 minutes (preferably, 0.5-5 minutes). The drying time naturally varies depending on the coating amount, but usually the above range is appropriate.

  As a method of applying the second coating liquid before the reduced rate of drying is exhibited, (1) a method of further applying the second coating liquid on the coating layer, and (2) a method of spraying by a method such as spraying (3) A method of immersing the support on which the coating layer is formed in the second coating liquid.

  In the method (1), examples of the application method for applying the second coating liquid include curtain flow coaters, extrusion die coaters, air doctor coaters, bread coaters, rod coaters, knife coaters, squeeze coaters, reverse roll coaters, A known coating method such as a bar coater can be used. However, it is preferable to use a method in which the coater does not directly contact the first coating layer that has already been formed, such as an extrusion die coater, a curtain flow coater, or a bar coater.

The coating amount of the second coating solution, 5 to 50 g / m ² is generally, 10 to 30 g / m ² is preferred.

  After the application of the second coating liquid, it is generally heated at a temperature of 40 to 180 ° C. for 0.5 to 30 minutes, and dried and cured. Especially, it is preferable to heat at a temperature of 40 to 150 ° C. for 1 to 20 minutes. For example, when the cross-linking agent contained in the first coating liquid is borax or boric acid, heating at a temperature of 60 to 100 ° C. is preferably performed for 5 to 20 minutes.

  When the basic solution (second coating solution) is applied at the same time as the coating solutions (1) and (2) (first coating solution) are applied, the first coating solution and the second coating solution are used as the first coating solution. The ink receiving layer can be formed by simultaneously coating (multilayer coating) on the support so that the coating solution is in contact with the support, followed by drying and curing.

  The simultaneous coating (multilayer coating) can be performed by a coating method using, for example, an extrusion die coater or a curtain flow coater. After the simultaneous coating, the formed coating layer is dried. In this case, the drying is generally performed by heating the coating layer at a temperature of 40 to 150 ° C. for 0.5 to 10 minutes, preferably at a temperature of 40 It is carried out by heating at -100 ° C for 0.5-5 minutes.

  When the simultaneous coating (multilayer coating) is performed by, for example, an extrusion die coater, at least three types of coating liquid discharged at the same time are close to the discharge port of the extrusion die coater, that is, before moving onto the support. In this state, a multilayer is applied on the support. Since at least three layers of the coating liquid layered before coating are likely to cause a crosslinking reaction at the interface of at least the three liquids when transferred to the support, at least 3 of the coating liquid is discharged near the discharge port of the extrusion die coater. The liquid tends to thicken by mixing, which may hinder the application operation. Therefore, when applying simultaneously as described above, it is preferable to apply the multiple coating layers simultaneously with the application of the first coating solution and the second coating solution, with a barrier layer solution (intermediate layer solution) interposed between the two solutions. .

  The barrier layer solution can be selected without particular limitation. For example, an aqueous solution containing a trace amount of water-soluble resin, water, and the like can be given. The water-soluble resin is used in consideration of applicability for the purpose of a thickener and the like. For example, cellulose resin (for example, hydroxypropylmethylcellulose, methylcellulose, hydroxyethylmethylcellulose) And polymers such as polyvinylpyrrolidone and gelatin. Here, the mordant may be contained in the barrier layer solution.

  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 calendering process may cause a decrease in the porosity (that is, the ink absorbability may be decreased), so it is necessary to set the conditions under which the decrease in the porosity is small.

  As roll temperature in performing the said 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 inkjet recording, the thickness of the ink receiving layer in the present invention 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.

  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 “Bore 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” manufactured by Suga Test Instruments Co., Ltd.

  Moreover, the 2nd coating liquid (basic solution) containing surfactant can be prepared as follows, for example. That is, a mordant (for example, 0.1 to 5.0% by mass) and a surfactant (for example, a total amount of 0.01 to 1.0% by mass) in ion-exchanged water and a crosslinking agent (0 to 0 as necessary). 5.0% by mass) and sufficiently stirred. The pH of the basic solution (second coating solution) is 7.1 or higher, and preferably 8.0 or higher. The pH can be adjusted appropriately to pH 7.1 or higher using aqueous ammonia, sodium hydroxide, calcium hydroxide, amino group-containing compounds (ethylamine, ethanolamine, diethanolamine, polyallylamine, etc.) and the like.

  Moreover, water, an organic solvent, or these mixed solvents can be used as a solvent used for preparation of each coating liquid. Examples of organic solvents that can be used in the coating solution 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. Can be mentioned.

  The latex can be used by adding to at least one of the first coating liquid and the second coating liquid (basic solution) as described above, but sufficiently mixed with the fine particles and the binder in the first coating liquid. From the viewpoint of effectively preventing bleeding over time over a long period of time, a mode in which the first coating liquid (the coating liquid (1) and / or the coating liquid (2)) is contained is preferable. At this time, it is not always necessary to include all of the latex in the first coating liquid, and it is also effective to include at least a part of the latex in the second coating liquid, thereby effectively preventing bleeding over time. be able to.

(mordant)
The mordant contained in the basic solution will be described.
In the present invention, a mordant is preferably contained in the ink receiving layer in order to improve the water resistance and aging resistance of the formed image. As the mordant, any of an organic mordant such as a cationic polymer (cationic mordant) and an inorganic mordant such as a water-soluble metal compound can be used. Of these, organic mordants are preferred.
In a preferred embodiment, the mordant is present so that the thickness of the portion where the mordant is present from the surface of the ink receiving layer is 10 to 60% with respect to the total thickness of the ink receiving layer. As described above, for example, (1) the coating solutions (1) and (2) are simultaneously applied to form a coating layer containing fine particles, a binder and a crosslinking agent, and the basic solution containing a mordant ( A method of applying a second coating liquid) thereon, (2) a method of applying a multilayer coating of the coating liquids (1) and (2) and the basic solution (second coating liquid) containing a mordant, etc. It can be formed by any method. The basic solution (second coating solution) may contain fine particles, a binder, a crosslinking agent, and the like. When configured as described above, since a large amount of mordant is present in a required portion of the ink receiving layer, the ink color material of the ink jet is sufficiently mordanted, the color density and bleeding over time, the gloss of the printed part, and the characters and images after printing. It is preferable because water resistance and ozone resistance are further improved. Part of the mordant may be contained in the layer initially provided on the support, and in that case, the mordant to be applied later may be the same or different.

  Examples of the water-soluble polyvalent metal salt compound used in the present invention include the above-mentioned water-soluble polyvalent metal compounds. In addition, the presence of the mordant in at least the upper layer of the ink receiving layer allows interaction with an ink-jet liquid ink having an anionic dye as a coloring material, thereby stabilizing the coloring material and water resistance. In addition, bleeding can be further improved.

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.
The following cationic mordant can be used as the cationic polymer used in the fine particle dispersion in the coating liquid (1).

  Examples of the polymer mordant include a homopolymer of a monomer having a primary to tertiary amino group and a salt thereof, or a monomer having a quaternary ammonium base (hereinafter sometimes referred to as “mordant monomer”), What is obtained as a copolymer or a condensation polymer of a mordant monomer and another monomer (hereinafter sometimes referred to as “non-mordant polymer”) is preferable. These polymer mordants can be used in any form of a water-soluble polymer or water-dispersible latex particles.

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

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

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

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

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

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

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

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

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

  The molecular weight of the mordant is preferably 2000 to 300000 in terms of weight average molecular weight. When the molecular weight is within this range, water resistance and aging resistance can be further improved.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In this example, an ink jet recording sheet is prepared as an example of the ink jet recording medium, and “parts” and “%” in the examples represent mass standards unless otherwise specified. .

[Example 1]
(Production of support)
50 parts of LBKP made of acacia and 50 parts of LBKP made of aspen were each beaten to 300 ml of Canadian freeness by a disc refiner to prepare a pulp slurry.
Next, in the pulp slurry obtained above, per starch, cationic starch (CAT 0304L manufactured by NSC Japan) 1.3%, anionic polyacrylamide (DA4104 manufactured by Seiko PMC Co., Ltd.) 0.15%, alkyl ketene dimer (Arakawa Chemical Size Pine K) 0.29%, Epoxidized behenamide 0.29%, Polyamide polyamine epichlorohydrin (Arakawa Chemical Co., Ltd. Arafix 100) 0.32%, then added antifoam 0.12% Was added.

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

After the corona discharge treatment was performed on the wire surface (back surface) side of the obtained base paper, high-density polyethylene was coated to a thickness of 25 μm using a melt extruder, and a thermoplastic resin layer comprising a mat surface was formed. (Hereinafter, this thermoplastic resin layer surface is referred to as “back surface”). The thermoplastic resin layer on the back side is further subjected to corona discharge treatment, and then, as an antistatic agent, aluminum oxide (“Alumina Sol 100” manufactured by Nissan Chemical Industries, Ltd.) and silicon dioxide (manufactured by Nissan Chemical Industries, Ltd.). “Snowtex O”) was dispersed in water at a mass ratio of 1: 2 so that the dry weight was 0.2 g / m ² . Subsequently, the surface was subjected to corona treatment, and polyethylene having a density of 0.93 g / m ² having 10% by mass of titanium oxide was coated using a melt extruder so as to be 24 g / m ² .

(Preparation of silica dispersion)
(1) Gas phase method silica fine particles having the following composition, (2) ion-exchanged water, (3) dispersant, and (4) zirconyl acetate are mixed, and bead mill (KD-P, Shinmaru Co., Ltd.) is mixed. After that, the dispersion was heated to 45 ° C. and held for 20 hours to obtain a silica dispersion.
〔composition〕
(1) Gas phase method silica fine particles 15.0 parts (Nippon Aerosil Co., Ltd., average primary particle size 7 nm, AEROSIL 300 SF75)
(2) Ion-exchanged water 82.9 parts (3) "Charol DC-902P" (51.5% aqueous solution) 1.31 parts (Daiichi Kogyo Seiyaku Co., Ltd .; dispersant)
(4) "ZA-30" (zirconyl acetate) 0.8 part (Daiichi Rare Element Chemical Co., Ltd.)

(Preparation of coating liquid A-1 for ink receiving layer)
(5) Diethylene glycol monobutyl ether acetate, (6) boric acid, (7) dimethylamine, epichlorohydrin, polyalkylene polyamine polycondensate and (8) polyvinyl alcohol in the following composition in 59.5 parts of the silica dispersion: The solution, (9) “Superflex 650”, (10) Synthetic alcohol, and (11) Ion-exchanged water were added at 30 ° C. to prepare an ink-receiving layer coating solution A-1. The pH was 3.6.

[Composition of coating liquid A-1 for ink receiving layer]
-59.5 parts of the silica dispersion (5) 0.6 part of diethylene glycol monobutyl ether acetate (Kyowa Hakko Chemical Co., Ltd., Butisenol 20 acetate)
(6) Boric acid (crosslinking agent) 0.45 parts (7) Dimethylamine / epichlorohydrin / polyalkylene polyamine polycondensate
0.2 parts (manufactured by Hymo Co., Ltd., 50% aqueous solution, SC-505)
(8) Polyvinyl alcohol solution 26.0 parts-Solution composition-
Polyvinyl alcohol 2.3 parts (manufactured by Kuraray Co., Ltd., “PVA235”, saponification degree 88%, polymerization degree 3500)
・ Polyoxyethylene lauryl ether 0.06 parts (manufactured by Kao Corporation, surfactant, Emulgen 109P)
・ Ion-exchanged water 23.64 parts (9) “Superflex 650” (cation-modified polyurethane) 1.1 parts (Daiichi Kogyo Seiyaku Co., Ltd.)
(10) Synthetic alcohol 2.3 parts (Nippon Alcohol, AP-7)
(11) 9.85 parts of ion exchange water

(Preparation of coating liquid A-2 for ink receiving layer)
In the preparation of the ink-receiving layer coating liquid A-1, the ink-receiving layer was coated in the same manner except that (6) boric acid was changed to 0 parts and (11) ion-exchanged water was changed to 10.3 parts. A liquid A-2 (coating liquid (1)) was prepared. The pH was 3.6.

(Composition of dura mating accelerating liquid B)
The following composition was mixed to prepare a dura accelerating liquid B. The pH was 7.8.
[Composition of Dura Acceleration Solution B]
・ Boric acid 0.65 part ・ Zirconyl ammonium carbonate 1.18 parts (Daiichi Rare Element Chemical Co., Ltd., 28% aqueous solution, zircosol AC-7)
・ Ammonium carbonate (first grade) 5.0 parts (Kanto Chemical Co., Ltd.)
・ Ion-exchanged water 63.17 parts ・ Polyoxyethylene lauryl ether 30.0 parts (manufactured by Kao Corporation, surfactant (2% aqueous solution), Emulgen 109P)

(Preparation of thickening accelerator C-1)
The following composition was mixed to prepare a thickening accelerator C-1. The pH was 4.3.
[Composition of thickening accelerator C-1]
・ Basic polyaluminum chloride 3.0 parts (manufactured by Daimei Chemical Industry Co., Ltd., water-soluble polyvalent metal salt, alpha-in 83)
・ Ion-exchanged water 12.0 parts ・ Polyoxyethylene lauryl ether 0.1 part (manufactured by Kao Corporation, surfactant (2% aqueous solution), Emulgen 109P)

(Preparation of thickening accelerator C-2)
The following composition was mixed to prepare a thickening accelerator C-2. The pH was 4.3.
[Composition of thickening accelerator C-2]
・ Basic polyaluminum chloride 15.0 parts (manufactured by Daimei Chemical Co., Ltd., water-soluble polyvalent metal salt, alpha-in 83)
・ Polyoxyethylene lauryl ether 0.1 part (manufactured by Kao Corporation, surfactant (stock solution), Emulgen 109P)

(Preparation of thickening accelerator C-3)
The following composition was mixed to prepare a thickening accelerator C-3. The pH was 3.8.
[Composition of thickening accelerator C-3]
・ Boric acid 0.5 part ・ Ion-exchanged water 13.5 parts ・ Gelatin 1.0 part ・ Polyoxyethylene lauryl ether 0.1 part (manufactured by Kao Corporation, surfactant (stock solution), Emulgen 109P)

[Comparative Example 1]
-Preparation of inkjet recording sheet-
After performing a corona discharge treatment on the front surface of the support, an aqueous polyaluminum chloride solution diluted 5 times in the ink receiving layer coating solution A-1 so as to have a coating amount of 173 ml / m ² thereon. (Alfine 83, manufactured by Daimei Chemical Industry Co., Ltd.) was applied by in-line mixing at a rate of 10.8 ml / m ² for coating. Then, it dried at 70 degreeC (wind speed 3-8 m / sec) with the hot air dryer, and produced the inkjet recording medium of the comparative example 1. FIG.
In the produced inkjet recording medium of Comparative Example 1, many fine cracks having a size of 1 to 2 mm were generated. In addition, many application stripes were generated in the application process.

[Example 1]
-Preparation of inkjet recording sheet-
After performing a corona discharge treatment on the front surface of the support, 15 ml / m ² of a thickening accelerator C-3 and 173 ml / m ^{2 of} an ink receiving layer coating solution A-2 are used to accelerate the thickening. Simultaneous coating was applied so that the agent was in direct contact with the support and the ink-receiving layer coating liquid A-2 was coated on the thickening accelerator C-3. The ink receiving layer coating solution A-2 was coated by in-line mixing a polyaluminum chloride aqueous solution (Alfine 83, manufactured by Daimei Chemical Industry Co., Ltd.) at a rate of 10.8 ml / m ² . . Then, it dried at 70 degreeC (wind speed 3-8 m / sec) with the hot air dryer, and produced the inkjet recording medium of Example 1. FIG.

[Example 2]
-Preparation of inkjet recording sheet-
After performing the corona discharge treatment on the front surface of the support, 15 ml / m ² of the thickening accelerator C-3, 173 ml / m ² of the ink receiving layer coating liquid A-2, and 15 ml / m ² of the support surface. The thickening accelerator C-1 is in direct contact with the support, and the ink receiving layer coating liquid A-2 is applied onto the thickening accelerator C-3. Further, simultaneous multilayer coating was performed so that the thickening accelerator C-1 was coated on the ink receiving layer coating liquid A-2. Then, it dried at 70 degreeC (wind speed 3-8 m / sec) with the hot air dryer, and produced the inkjet recording medium of Example 2. FIG.

[Example 3]
-Preparation of inkjet recording sheet-
After performing the corona discharge treatment on the front surface of the support, 15 ml / m ² of the thickening accelerator C-3, 173 ml / m ² of the ink receiving layer coating liquid A-2, and 15 ml / m ² of the support surface. The thickening accelerator C-2 is in direct contact with the support, and the ink receiving layer coating liquid A-2 is applied onto the thickening accelerator C-3. Further, simultaneous multilayer coating was performed so that the thickening accelerator C-2 was coated on the ink receiving layer coating liquid A-2. Then, it was dried with a hot air dryer at 80 ° C. (wind speed 3 to 8 m / sec) until the solid content concentration of the coating layer became 20%. This coating layer showed constant rate drying during this period. Then, before showing the rate-decreasing drying, the film was immersed in the dura accelerating liquid B for 2 seconds to adhere 13 g / m ² on the coating layer, and further dried at 80 ° C. for 10 minutes. An ink jet recording medium was produced.

[Example 4]
-Preparation of inkjet recording sheet-
After performing a corona discharge treatment on the front surface of the support, 173 ml / m ² of the ink receiving layer coating liquid A-1 and 15 ml / m ² of the thickening accelerator C-2 were added to the ink receiving layer. The coating solution A-1 was applied to the support directly, and the thickening accelerator C-2 was applied simultaneously on the ink receiving layer coating solution A-1. Then, it was dried with a hot air dryer at 80 ° C. (wind speed 3 to 8 m / sec) until the solid content concentration of the coating layer became 20%. This coating layer showed constant rate drying during this period. Then, before showing the rate-decreasing drying, the film was immersed in the dura accelerating liquid B for 2 seconds to adhere 13 g / m ² on the coating layer, and further dried at 80 ° C. for 10 minutes. An ink jet recording medium was produced.

(Evaluation test)
The ink jet recording medium obtained above was subjected to the following evaluation test. The results are shown in Table 1 below.
(1) Microcracking The coated surface was evaluated by measuring the number of cracks having a size of 30 μm or more.
The evaluation criteria are as follows.
○: 0 / m ²
Δ: 1 to 15 pieces / m ²
×: 15 pieces / m ² or more

(2) Coated muscle The coated muscle was evaluated by measuring the number of coated muscles having a size of 100 μm or more.
The evaluation criteria are as follows.
○: 0 / m ²
Δ: 1 to 15 pieces / m ²
×: 15 pieces / m ² or more

(3) Ozone resistance Using an inkjet printer (“PMG800” manufactured by Seiko Epson Corporation), magenta and cyan solid images were printed on each inkjet recording medium so that OD = 1.0, and ozone It was stored for 48 hours in a 10 ppm concentration environment. The OD of magenta and cyan before and after storage was measured with a reflection densitometer (“Xrite 938” manufactured by Xrite), and the OD residual ratio of magenta and cyan was calculated.

(4) Thickening In the ink receiving layer coating liquid (corresponding to the coating liquid (1) in the present invention) used in each example, each thickening promoting liquid (coating liquid (in the present invention ( 2), and the viscosity after 24 hours was measured at 40 ° C. Compare the viscosity before and after the addition of the thickening accelerator, and the viscosity after addition of the thickening accelerator is evaluated as “◯” when the viscosity is 1.5 times or more of the viscosity before addition. Evaluated as “x”. As a result, increase in the viscosity of the ink receiving layer coating solution was observed in all Examples.
In Comparative Example 1, since no thickening accelerator was added, “-” was marked as not corresponding to this evaluation.

  From Table 1, the inkjet recording medium of the Example which apply | coated coating liquid (1) (coating liquid for ink receptive layers) and coating liquid (2) (thickening accelerator) by multilayer coating by the manufacturing method of this invention is shown. It can be seen that there is no microcracking or coating streaks, and the coating surface shape, coating streaks and ozone resistance are excellent. On the other hand, Comparative Example 1 in which the water-soluble polyvalent metal salt was added in-line was inferior in all of the coated surface shape, the coated stripe, and the ozone resistance.

Claims (12)

A method for producing an ink jet recording medium comprising an ink receiving layer forming step of forming an ink receiving layer on a support,
In the ink receiving layer forming step, the coating liquid (1) in which at least one kind of fine particles are dispersed in at least one kind of cationic polymer and a binder are mixed, and the coating liquid (1) is thickened. A coating liquid (2) capable of being coated on the support, and the coating liquid (1) and the coating liquid (2) have an pH of 8 or less. A method for manufacturing a recording medium.   The method for producing an ink jet recording medium according to claim 1, wherein the coating liquid (2) contains a crosslinking agent capable of crosslinking the binder.   The method for producing an inkjet recording medium according to claim 2, wherein the crosslinking agent is a boron-containing compound.   The method for producing an ink jet recording medium according to claim 1, wherein the coating liquid (2) contains a water-soluble polyvalent metal salt.   The fine particles are at least one selected from organic fine particles, silica fine particles, colloidal silica, alumina fine particles, and pseudo-boehmite type aluminum hydroxide fine particles. A method for producing an inkjet recording medium.   The coating solution (2) containing a crosslinking agent, the coating solution (1), and the coating solution (2) containing a water-soluble polyvalent metal salt are laminated in this order so as to be laminated from the support side. The method for producing an ink jet recording medium according to claim 1.   The method for producing an ink jet recording medium according to any one of claims 1 to 6, wherein the fine particles are gas phase method silica having an average primary particle diameter of 30 nm or less.   The latex containing at least a cation-modified polymer is used in the ink receiving layer forming step, and the average particle size of the cation-modified polymer is 0.1 μm or less. 8. A method for producing an ink jet recording medium according to any one of 7 above.   9. The method for producing an ink jet recording medium according to claim 8, wherein the latex containing the cation-modified cation-modified polymer is an aqueous dispersion of a cationic urethane resin.   In the coating step, the coating solution (1) and the coating solution (2) are applied in multiple layers to form a coating layer, or the coating solution (1) and the coating solution (2) are applied in multiple layers. At any time during the drying of the coating layer to be formed and before the coating layer exhibits a reduced rate of drying, a basic solution having a pH of 7.1 or higher is applied to the coating layer and crosslinked and cured. The method for producing an ink jet recording medium according to claim 1, wherein the ink receiving layer is formed.   An ink jet recording medium obtained by the method for producing an ink jet recording medium according to any one of claims 1 to 10.   12. The ink jet recording medium according to claim 11, wherein 30% by mass or more of the total amount of the water-soluble polyvalent metal salt contained in the ink receiving layer is in a range of 5 μm from the surface of the ink receiving layer.