JP2006137034A - Method for manufacturing inkjet recording medium and inkjet recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a silver salt photograph-like glossy inkjet recording medium which has an excellent clarity of a dye ink image and best-suitability for continuous printing because of the remote occurrence of image feathering or color tone change, even in case of an overlay with the recording medium right after printing. <P>SOLUTION: This method for manufacturing an inkjet recording medium with a porous ink acceptance layer comprises (a) a process "a" to apply to the surface of a base material, an aqueous coating material containing a micropigment and a hydrophilic resin which forms a hydrogel by irradiating an aqueous liquid with activation energy beams, and then hydrogelatinize the aqueous coating material coating layer by irradiation with the activation energy beams, (b) a process "b" to apply a coating liquid containing at least a chemical compound with a cationic nature to the surface of the layer formed by the process "a", and if necessary, (c) a process "c" to apply a coating liquid for a glossy layer containing at least the micropigment to the surface of the formed layer, press the coating liquid layer for the glossy layer with a press roll so as to allow this layer to come into contact with a glossing roll, and form the glossy layer by drying the coating liquid layer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  INDUSTRIAL APPLICABILITY The present invention is a silver salt photographic glossy inkjet recording material suitable for continuous printing because it is excellent in the clarity of dye ink images and hardly causes bleeding and color tone changes even when the recording materials are laminated immediately after printing. Regarding the method.

  Various output systems such as a wire dot recording system, a thermal coloring recording system, a melt thermal transfer recording system, a sublimation recording system, an electrophotographic system, and an ink jet recording system have been developed so far. Above all, the inkjet recording method is recognized as a recording method suitable for personal use because of the fact that plain paper can be used as a recording sheet, the running cost is low, and the hardware is compact and inexpensive. Has stretched to. With the spread of hardware, full-color, high-speed, and high-quality image development has rapidly progressed, so output applications have expanded from simple monochrome text output to digital image output that can replace silver halide photography. However, inevitably, the quality required for the recording paper side has become stricter.

  Among ink jet recording papers currently on the market, the sales volume of glossy paper is increasing as a medium that can output a silver salt photographic full-color image. In the technology for producing glossy paper, how to achieve both “ink absorption and gloss” is an important key.

  In order to satisfy the “ink absorbability” required for glossy paper, it is necessary to absorb the ejected ink quickly and in large quantities. Many commercially available photographic glossy inkjet papers meet this requirement by using a fine pigment with a high pore volume as the main component of the ink-receiving layer, but the pore diameter is very high with a high pore volume. Small fine pigments tend to crack in the receiving layer due to capillary shrinkage in the drying process after coating, and with a normal coating facility, the coating amount sufficient for ink absorption (ie, the pore volume of the ink receiving layer) Difficult to get. Multi-stage coating and long-time drying are effective for gradually reducing the stress during drying caused by capillary contraction, but poor operational efficiency is a problem.

  Therefore, in order to suppress cracks that occur during drying, many of the photographic ink-jet glossy papers currently produced use polyvinyl alcohol as a binder for the ink receiving layer and a boron compound that crosslinks polyvinyl alcohol as a hardener. Many combinations are used. As a method for adding a boron compound as a hardener, as disclosed in JP-A No. 2001-341414 (Patent Document 1), it is preliminarily mixed with a paint for an ink receiving layer, or JP-A No. 11-192777 (Patent Document). As seen in Reference 2), many proposals have been made such as applying a boron compound-containing solution to the ink-receiving layer after coating at a timing before exhibiting a reduced drying rate. The porous pigment layer hardened by the reaction tends to be very fragile, and has a disadvantage that the coating film after drying is easily cracked due to slight deformation such as bending or environmental change of temperature and humidity. The present inventors also applied the coating layer crosslinked with these boron compounds because the crosslinking reaction of polyvinyl alcohol by the boron compound further proceeds when exposed to a relatively high temperature and high humidity environment for a long time. It was confirmed that innumerable cracks occurred on the surface. Conversely, even in a low-humidity environment, the moisture content contained in the coating layer decreases, so the coating layer becomes even more brittle or cracks occur even in mild deformation such as paper passing through the printer. I found out. In addition, in the case of roll-shaped recording paper often used for business purposes, it was difficult to remove curl due to the stiffening of the coating film, and there was an effect that the handling of the recording paper after printing was hindered.

  In order to overcome these problems due to boron crosslinking, an organic crosslinking agent (for example, JP 2001-146068 A: Patent Document 3) and a temperature sensitive resin (for example, JP 2003-103904 A: Patent) It has also been proposed to reduce the amount of boron-based compounds used in combination with literature 4). However, the reaction rate of organic crosslinking agents and thermosensitive resins is slower than the gelation reaction of boron compounds, and it is difficult to carry out sufficient reaction on the actual production line. Thus, it is practically impossible to greatly reduce the amount of boron compound used.

  Furthermore, boron compounds are subject to effluent control substances due to the amendment of the Enforcement Order of the Water Pollution Prevention Law in 2001, and there are concerns about their hazards, so the spread of them to general households as an alternative to silver halide photography It is desirable not to use it as a recording paper material.

  Therefore, the present inventors have disclosed, as a means for suppressing cracks without depending on a crosslinking reaction with a boron compound, in Japanese Patent Application Laid-Open No. 2002-160439, “In an inkjet recording body having one or more coating layers on a substrate, at least One layer is coated with a water-based paint containing a fine pigment and a hydrophilic resin that does not have a radically polymerizable unsaturated bond and forms an hydrogel by irradiating an aqueous solution with an electron beam. An ink jet recording body, which is a porous ink-receiving layer formed by irradiating and hydrolyzing the coating layer and then drying, was proposed (see Patent Document 5). In this method, when an aqueous coating layer is irradiated with an electron beam, hydrogen is extracted due to the direct effect of the electron beam and the indirect effect of the radiolyzed water, and it becomes an active species. “There is no radical polymerizable unsaturated bond It is presumed that a cross-linking reaction is established by bonding “general-purpose hydrophilic resins” to each other. This cross-linking reaction proceeds in a short time in an aqueous solution state in which the network structure of the molecular chain is sufficiently spread. Therefore, the cross-linking structure becomes excessively densified, such as boron cross-linking, or the ink jet recording medium is gradually stored during storage. There is no concern that the crosslinking reaction proceeds and the coating film becomes rigid. Therefore, even when stored in a high-temperature and high-humidity environment with a temperature of 40 ° C. and a humidity of 90% as in the case of a boron cross-linked coating film, the coating layer surface did not crack. With the recent widespread use of inkjet printers, the environment in which printed materials are stored has been diversified, and thus the above-described high-temperature and high-humidity environment can be said to be an environmental test that should be sufficiently assumed in indoors in summer.

However, although the coating layer obtained as described above was a porous ink-receiving layer without cracks, it did not have a glossiness at a level that could replace silver salt photography.
Therefore, as a method for obtaining a surface gloss as high as that of a silver salt photograph, we have described "a subbing layer having a pigment and an adhesive on a low-permeability or non-permeability base material or on the base material." Above, a fine pigment and a hydrophilic resin that does not have a radical polymerizable unsaturated bond and forms a hydrogel by irradiating an aqueous solution with an electron beam, with respect to 100 parts by mass of the fine pigment, A porous ink-receiving layer is formed by applying a water-based paint containing 1 to 100 parts by weight of a hydrophilic resin, and then irradiating with an electron beam to hydrogel the coating layer, followed by drying. Forming a glossy coating liquid layer, then pressing the coating liquid layer with a press roll so as to contact the glossy roll, and drying the coating liquid layer with a glossing means comprising a gloss layer. Ink characterized by forming The manufacturing method "of the jet recording material has already been filed.
As a result of further investigation on this manufacturing method, it is not necessary to limit the base material to a low-permeability or non-permeability base material, and even measures against shrinkage and wrinkles that are likely to occur due to tension during application process and swelling due to liquid absorption. It has been found that if consideration is given, a gas-permeable substrate can also be used.

  On the other hand, in addition to the widespread use of digital cameras and inkjet printers equipped with direct print functions as standard equipment, recording paper manufacturers have strengthened the sale of L-size recording paper familiar to users as silver halide photographs, and personal computers. The printing speed has been shortened due to improvements in printer specifications, and the ink and light resistance of dye inks have been greatly improved, as typified by the inks installed in new inkjet printer models that have been released in recent years. Since it was close to silver halide photography, the opportunity to output to glossy recording paper as an alternative to silver halide photography more easily than ever in ordinary households has increased. In these new printers, since the conveyance mechanism of the recording medium has been improved, troubles such as double feeding are considerably reduced even when a plurality of sheets are printed. For this reason, a general user prints a plurality of sheets without worrying about the operating state of the printer during printing, and the recording bodies are stacked one after another immediately after the ink is sprayed to form an image. There are many cases. Usually, the base material of silver halide photographic glossy recording paper is made of non-permeable material such as resin-coated paper to prevent undulation and feel close to photographic paper, or coated on the back side of the base material. Since the layer is often provided, the ink solvent is extremely difficult to volatilize from the recording medium laminated in such a state. It is estimated that most of the solvent for general-purpose ink jet printer ink volatilizes if the recording medium after printing is left in a state where the recording surface is opened, and dye fixing proceeds at that time. Alternatively, the same effect can be expected even if paper with a high liquid absorption property is pressed and the solvent is half-forced. However, if a state in which the ink solvent remains in the above-described layered state occurs, dye diffusion is delayed and diffusion proceeds.Therefore, even after the layered state is canceled and the ink solvent is volatilized, bleeding and color misregistration occur in the image. Will occur.

  In order to avoid this phenomenon, it is presumed that a composition containing a high concentration of a cationic compound as a dye fixing agent in the vicinity of the surface layer of the recording medium is effective for the purpose of quickly fixing the dye before diffusion. For example, as disclosed in JP-A-60-61887 (Patent Document 6), polyalkyleneamines that have been known for a long time as ink fixing agents for ink jet recording materials because of their excellent ink fixing ability, "Water-soluble cationic resin containing a primary amine structure" such as a cationic resin containing a five-membered ring amidine structure, which is disclosed in Japanese Patent Application Publication No. 2004-122769 (Patent Document 7) and has good image storage stability of dye ink, or It describes that a cationic polyvalent metal salt compound is blended.

We have already proposed a porous ink receiving layer in which an aqueous paint coating layer containing a hydrophilic resin and a fine pigment is hydrogelated by irradiation with active energy rays on the substrate, and on the porous ink receiving layer An inkjet recording body having a porous ink-receiving layer and a glossy layer sequentially laminated on a substrate having a fine pigment and a glossy layer containing a water-soluble cation resin laminated on the substrate ” It is close to the configuration. This recording medium has good rub resistance of the pigment ink printing part and image sharpness of the dye ink, and has the merit that it can be manufactured with relatively few processes, but it is capable of printing multiple sheets, particularly in a high temperature and high humidity environment. In the laminated state by continuous printing, bleeding and color tone shift could not be completely suppressed. If too much a water-soluble cationic resin as a fixing agent was added for improvement, the ink absorbability was lowered, and it was impossible to achieve both performances.
JP, 2001-341414, A Example 1 Japanese Patent Laid-Open No. 11-192777. JP, 2001-146068, A Claims 1-3 JP, 2003-103904, A Claims 1-3 JP, 2002-160439, A Claim 1 JP-A-60-61887 JP, 2004-122769, A Claim 1

  An object of the present invention is to provide a silver salt photographic glossy inkjet recording material suitable for continuous printing because it is excellent in the clarity of a dye ink image and hardly bleeds or changes in color even when the recording material is laminated immediately after printing. It is to provide.

The present invention adopts the following configuration in order to solve the above problems. That is,
(1) On the base material, (a) a water-based paint containing a fine pigment and a hydrophilic resin that forms a hydrogel by irradiating an aqueous solution with active energy rays is applied, and then irradiated with active energy rays. And a step (a) of hydrogelating the aqueous paint coating layer, and (b) a step b of applying a coating solution containing at least a cationic compound on the layer formed by the step a. A method for producing an ink jet recording material having a porous ink receiving layer.

(2) On the substrate, apply a water-based paint containing (a) a fine pigment and a hydrophilic resin that forms a hydrogel by irradiating an aqueous solution with active energy rays, and then irradiate with active energy rays. Step a for hydrogelating the aqueous paint coating layer, Step b for applying a coating solution containing at least a cationic compound on the layer formed in Step (b), Step (c) On the layer formed by b, a gloss layer coating liquid containing at least a fine pigment is applied, and then pressed with a press roll so that the gloss layer coating liquid layer is in contact with the gloss roll. A method for producing an ink jet recording material having a porous ink receiving layer, comprising the step c of drying to form a glossy layer.

(3) Apply a water-based paint containing (a) a fine pigment and a hydrophilic resin that forms a hydrogel by irradiating an aqueous solution with active energy rays on the substrate, and then irradiate with active energy rays. Step (a) for hydrogelating the aqueous paint coating layer, and (d) Applying a gloss layer coating solution containing at least a fine pigment on the layer formed in Step a, and then coating the gloss layer Step d in which the liquid layer is pressed with a press roll so as to be in contact with the gloss roll, and the coating liquid layer is dried to form a gloss layer; and (e) at least cationic on the layer formed in step d. A method for producing an ink jet recording body having a porous ink receiving layer, comprising a step e of applying a coating liquid containing a compound.

(4) The inkjet according to any one of (1) to (3), wherein the substrate is a substrate having an undercoat layer containing a pigment and a binder at least on the side on which the ink receiving layer is formed. A method for manufacturing a recording medium.

(5) The ink jet recording material according to any one of (1) to (4), wherein the cationic compound contained in the coating solution of step b or step e is a water-soluble cationic resin. Production method.

(6) The water-soluble cationic resin that is the cationic compound is a polymer containing at least one of the following (X) and (Y) or a derivative thereof: (5) A method for producing an ink jet recording material.
(X) a monomer selected from ethyleneimine, vinylamine, and allylamine;
Polymerized structural unit (Y) 5-membered ring amidine structural unit

(7) The method for producing an ink jet recording material according to any one of (5) and (6), wherein the water-soluble cationic resin, which is the cationic compound, has an average molecular weight of 1,000 to 100,000.

(8) The ink jet recording material according to any one of (1) to (4), wherein the cationic compound contained in the coating liquid of step b or step e is a polyvalent metal salt compound. Manufacturing method.

(9) The production of the ink jet recording material according to any one of items (1) to (8), wherein the pH of the coating solution containing the cationic compound in step b or step e is 7 or more. Method.

(10) The fine pigment contained in the water-based paint serving as the ink receiving layer is silica having an average particle size of 500 nm or less and cationized by complexing with a water-soluble cationic resin (1) ) To (9) A method for producing an ink jet recording material according to any one of the items.

(11) The method according to any one of (1) to (10), wherein the active energy ray is an electron beam.

(12) An ink jet recording material having a porous ink receiving layer on a substrate, which is produced by the method according to any one of (1) to (11).

(13) Porous ink reception in which a water-based paint coating layer containing a hydrophilic resin and fine pigment is hydrogelated by irradiation with active energy rays and a cationic compound is adhered to the surface of the pores on the substrate An ink jet recording material having a layer.

(14) The ink jet recording material according to (8), wherein the active energy ray is an electron beam.

  As described above, the present inventor explained that the gloss layer paint contains fine pigments in addition to the water-soluble cationic resin, as a cause of the decrease in ink absorption that occurs when a large amount of the water-soluble cationic resin is added to the glossy layer. Therefore, it is easy to form a film by shock when laminating and coating on the ink receiving layer, and the glossy layer coating is pressed against the porous ink receiving layer by a roll press for glossing treatment, so that the glossy layer coating is in the porous ink receiving layer. It was speculated that the film was formed so as to close the pores.

  Therefore, when a coating solution containing a water-soluble cationic resin as a main component is separately applied on the porous ink receiving layer before forming the glossy layer, a desired cation amount can be added without reducing the ink absorbability. Thus, it was possible to obtain a recording material in which no blurring or color tone occurred in an image even in a laminated state by continuous printing in a high temperature and high humidity environment described above. In this case, since a water-soluble cation resin was separately applied, it was presumed that the water penetrated uniformly to the inside of the pores of the porous ink receiving layer without causing excessive aggregation or thickening. As a result of a detailed examination of this technique, the cationic compound can obtain a desired effect even if it is not a water-soluble cationic resin, and the glossy layer can be applied if the application time of the cationic compound does not interfere with the gloss of the glossy layer. It has been found that the gloss layer may not be formed depending on the manufacturing cost and application.

Japanese Patent Application Laid-Open No. 2003-103913 discloses a case in which a smoothing / metalling treatment is carried out after excessively applying a liquid containing the above-mentioned polyallylamine compound as a mordant together with a crosslinking agent on a porous coating layer before drying is completed. However, in this method, a cross-linking agent is added as an essential component to the coating solution containing a mordant, and the lower layer immediately thickens by application of the solution, thereby suppressing cracks that occur in the late stage of drying. Therefore, the purpose and the state of the coating layer obtained by coating are different from this case.

  Furthermore, since the “water-soluble cationic resin containing a primary amine structure” having a high ink fixing ability originally has a relatively high discoloration property, there is a concern that the discoloration property may be strengthened by irradiation with active energy rays. In addition, the coating material for forming a porous coating layer mainly composed of a fine pigment such as the ink receiving layer of the present invention causes relatively aggregation and thickening depending on the type and amount of the polyvalent metal salt compound. Because of its ease, there are problems with paint properties and stability when blended into paints. Further, when the cationic compound is added too much to the gloss layer, not only the ink absorbability is lowered, but there is also a problem that the releasability from the press roll to be pressed for the glossing treatment of the coating layer is deteriorated. For the above reasons as well, in order to add a high concentration of a cationic compound near the surface layer of an ink jet recording body having a porous ink receiving layer obtained by using active energy rays as in the present invention, the cationic compound must be separated. The method of adding as a coating solution was considered to be suitable, leading to the present invention.

  According to the present invention, there is provided a silver salt photographic glossy ink jet recording material suitable for continuous printing because it is excellent in the clarity of a dye ink image and hardly bleeds or changes in color tone even when the recording material is laminated immediately after printing. Provided.

(Base material)
Various substrates can be used for the ink jet recording material of the present invention as long as a coating layer serving as an ink receiving layer can be formed without any problem. In particular, when a base material having air permeability of less than 500 seconds / 100 ml is used, the coating layer is efficiently dried with a heated gloss roll in the gloss layer glossing step. Therefore, it is easy to obtain high ink absorption performance. In addition, the air-permeable base material may have a relatively low specific gravity, and thus has a high liquid-absorbing property, which is preferable in that the base material can also contribute to ink absorption. Since it expands due to liquid absorption, there is a side where wrinkles and bumps are likely to occur. When trouble occurs in this respect, it is effective to apply an undercoat layer or a backcoat layer. Moreover, a low air permeability or a non-air-permeable base material can be used conveniently at the point which does not need to worry about these.

In the present invention, the low-permeability or non-permeability base material is such that the Oken type air permeability is 500 seconds / 100 ml or more, preferably 800 seconds / 100 ml or more, more preferably 1000 seconds / 100 ml or more. It means a substrate. When such a base material is used, it is possible to prevent the penetration of water vapor or moisture into the base material itself, and it is possible to easily obtain an ink jet recording material having a photographic texture with reduced cockling and the like.
Examples of the base material that can be used include so-called resin-coated paper coated with polyethylene resin, so-called synthetic paper represented by YUPO (trade name: manufactured by YUPO Corporation), which has been subjected to special processing by stretching polypropylene. Cellophane, polyethylene, polypropylene, soft polyvinyl chloride, hard polyvinyl chloride, polyester (such as PET), films such as polystyrene, metallized paper, and papers with controlled air permeability. Of these, the use of resin-coated paper, synthetic paper, and film is preferred.

In particular, a support having polyethylene coated with titanium oxide and resin-coated on the paper surface is preferably used because the finished appearance is equivalent to that of photographic paper. 3-50 micrometers is preferable and, as for the thickness of a polyethylene coating layer, 5-30 micrometers is more preferable. When the thickness of the polyethylene coating layer is less than 3 μm, defects such as holes in the polyethylene resin tend to increase during resin coating, and there are many cases where it is difficult to control the thickness, and smoothness is difficult to obtain. Conversely, if it exceeds 50 μm, the effect obtained is small for the increase in cost.
In order to enhance the adhesion of the inner ink receiving layer described later, it is preferable to subject the resin layer surface to a corona discharge treatment or to provide a subcoat layer such as gelatin.

  As a paper base material used for so-called resin-coated paper coated with this polyethylene resin, those manufactured using wood pulp as a main material are used. As the wood pulp, various chemical pulps, mechanical pulps, regenerated pulps and the like can be used as appropriate, and these pulps can be adjusted in the beating degree by a beating machine in order to adjust paper strength, smoothness, papermaking suitability, and the like. The beating degree is not particularly limited, but generally about 250 to 550 ml (CSF: JIS-P-8121) is a preferable range. Also, chlorine-free pulp such as so-called ECF and TCF pulp can be preferably used. Moreover, a pigment can be added as needed. As the pigment, talc, calcium carbonate, clay, kaolin, calcined kaolin, silica, zeolite and the like are preferably used. Opacity and smoothness can be increased by adding a pigment, but if added excessively, paper strength may be reduced, and the amount of pigment added is preferably about 1 to 20% by mass with respect to wood pulp.

  Moreover, if a plastic film with excellent transparency such as polyethylene terephthalate, polyvinyl chloride, polycarbonate, polyimide, cellulose triacetate, cellulose diacetate, polyethylene, polypropylene is used as the base material, light transmission of back prints, OHP sheets, etc. An ink jet recording material that can be used as a recording medium can be produced. Since the ink receiving layer obtained in the present invention is highly transparent, it can be suitably used for these media.

These substrates can be applied with a subcoat layer or various easy adhesion treatments such as corona discharge treatment when the adhesive strength with the ink receiving layer formed on the surface is insufficient.
The thickness of the substrate is preferably 50 to 500 μm in consideration of the paper passing property of the printer. In particular, in the case of a water-absorbing substrate, if the substrate is too thin, there is a concern that the strength and dimensional stability when wet are reduced, so a relatively thick 100 to 500 μm is desirable.

In addition, a back layer can be provided on the side of the base sheet opposite to the ink receiving layer in order to suppress curling of the ink jet recording material and to improve transportability. In particular, when a base material having high air permeability or high water absorption is used, it is desirable to coat the back layer in order to make the hand feeling closer to the silver salt photograph. The composition of the back surface layer and the easy adhesion treatment of the back surface of the base material sheet accompanying it can be selected according to the application, and are not particularly limited. However, in view of coating properties and cost, the pigment and the hydrophilic resin It is preferable to provide a back surface layer containing as a main component. However, if the water absorption of the back surface layer is too high, it is not preferable because the recording medium immediately after printing laminated during continuous printing is stuck or sticky.
Furthermore, assuming double-sided printing, a coating layer including an ink receiving layer may be provided on both sides, and after applying an adhesive on the back surface, it may be combined with release paper in order to cope with labeling and sealing applications.
These back surface layers may be processed in advance on the substrate, or may be performed simultaneously with or after the processing of the coating layer including the ink receiving layer.

(Formation of undercoat layer)
In the ink jet recording material of the present invention, an undercoat layer having a pigment and a binder may be formed on the substrate. The undercoat layer can be provided with functions such as correcting the dimensional stability, smoothness, and color tone of the substrate, and quickly absorbing the solvent in the inkjet ink component. A colorant, that is, a dye in the ink-jet ink component that could not be fixed by the ink receiving layer may be fixed. In particular, when a water-absorbing substrate is used, it is desirable to coat an undercoat layer from the viewpoint of wet strength and dimensional stability as described above.

  Examples of the pigment used for the undercoat layer include transparent or white pigments such as colloidal silica, amorphous silica, alumina, aluminum hydroxide, magnesium carbonate, calcium carbonate, kaolin, and calcined kaolin. Pigments used in the ink receiving layer and the gloss layer can also be used. Of these, an especially preferred pigment is amorphous silica.

  When amorphous silica is used, the amorphous silica preferably has an average primary particle diameter of 3 to 70 nm and an average secondary particle diameter of 20 μm or less, an average primary particle diameter of 10 to 40 nm, and an average of 2 Those having a secondary particle size of 15 μm or less are more preferred. The average secondary particle diameter of the amorphous silica used for the undercoat layer is preferably larger than the average secondary particle diameter of the amorphous silica used for the ink receiving layer. When the average secondary particle diameter of the amorphous silica used for the undercoat layer is smaller than the average secondary particle diameter of the amorphous silica used for the ink receiving layer, the ink absorbability may be lowered.

As the binder of the undercoat layer, polyvinyl alcohol including proteins such as casein, soybean protein, synthetic protein, various starches such as starch and oxidized starch, polyvinyl alcohol, cationic polyvinyl alcohol, modified polyvinyl alcohol such as silyl modified polyvinyl alcohol , Cellulose derivatives such as carboxymethylcellulose and methylcellulose, styrene-butadiene copolymer, conjugated diene polymer latex of methyl methacrylate-butadiene copolymer, acrylic polymer latex, vinyl-based polymers such as ethylene-vinyl acetate copolymer Conventionally known binders generally used for coated paper such as polymer latex are used alone or in combination.
The blending ratio of the pigment and binder in the undercoat layer is generally adjusted in the range of 1 to 100 parts by weight, preferably 2 to 50 parts by weight with respect to 100 parts by weight of the pigment.

  A cationic compound can be added to the undercoat layer as necessary in order to catch ink penetrating from the ink receiving layer, fix the dye, impart water resistance, and improve the recording density. Typical cationic compounds include polyalkylene polyamines such as polyethylene polyamine and polypropylene polyamine or derivatives thereof, acrylic resins having secondary, tertiary amine groups and quaternary ammonium groups, polyvinyl amines, polyvinyl amidines, Dicyan cationic resin represented by dicyandiamide-formalin polycondensate, polyamine cationic resin represented by dicyandiamide-diethylenetriamine polycondensate, epichlorohydrin-dimethylamine addition polymer, diallyldimethylammonium chloride-sulfur dioxide copolymer, diallylamine Salt-sulfur dioxide copolymer, diallyldimethylammonium chloride polymer, allylamine salt polymer, dialkylamine (meth) acrylate quaternary salt polymer, acryloni Lil and N- vinyl acrylic amidine hydrochloride polymer and a hydrolyzate thereof, polyamidine-based resins, acrylamide - diallylamine can cationic resin is illustrative salt copolymers such as may be used alone or in combination of several types.

  In addition to the above components, the coating liquid for forming the undercoat layer further includes a dispersant, a thickener, an antifoaming agent, an antistatic agent, an antiseptic, a fluorescent dye used in the production of general coated paper. Various auxiliary agents such as a colorant are appropriately added.

The coating amount of the undercoat layer is about 0.5 to 30 g / m ² and can be formed by various known coating apparatuses such as a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a die coater, and a curtain coater. . In particular, the air knife coater is preferably used because it can deal with a wide range of paint properties and coating amounts. In addition, a die coater and a curtain coater are excellent in uniformity of coating amount, and are therefore preferable coating methods particularly for glossy ink jet recording materials for the purpose of high-definition recording.

(Formation of ink receiving layer)
In the ink jet recording material of the present invention, an ink receiving layer is formed on the above-mentioned substrate or an undercoat layer having a pigment and a binder formed on the substrate.
The ink receiving layer of the ink jet recording material of the present invention is coated with an aqueous paint containing a fine pigment and a hydrophilic resin that forms a hydrogel by irradiating an aqueous solution with active energy rays, and then irradiating with active energy rays. Then, the coating layer is a porous layer obtained by hydrogelation and drying.

  As the fine pigment used in the ink receiving layer, a fine pigment having an average particle diameter of 500 nm or less, more preferably 300 nm or less can be used to obtain a receiving layer having excellent ink absorbability, transparency and glossiness. However, the present invention is not limited to this. Here, the average particle diameter is a particle diameter (value obtained by cumulant method) measured by a dynamic light scattering method. Types are not limited, but commercially available pigments such as silica, aluminosilicate, kaolin, clay, calcined clay, zinc oxide, tin oxide, aluminum hydroxide, boehmite, pseudoboehmite, alumina, calcium carbonate, satin white, aluminum silicate, smectite, Various pigments known in the field of general coated paper or ink jet recording materials such as magnesium silicate, magnesium carbonate, magnesium oxide, diatomaceous earth, styrene plastic pigment, urea resin plastic pigment, and benzoguanamine plastic pigment can be used. Among these fine pigments, silica, aluminum hydroxide, boehmite, pseudoboehmite, and alumina are particularly suitable because they have a large pore volume and excellent ink absorbability.

  In order to obtain a highly glossy and highly transparent ink-receiving layer, as a fine pigment, primary particles having an average particle diameter of 3 to 40 nm aggregate to form secondary particles having an average particle diameter of 500 nm or less. Is preferably used. In particular, the particle diameter of the secondary particles is preferably 8 to 400 nm, more preferably 10 to 300 nm. Such secondary particles have a large pore volume because of voids inside the secondary particles. Furthermore, since the voids between the secondary particles can also be used for ink absorption, the ink absorption capability is high. In addition, since the primary particles are sufficiently smaller than the wavelength of light, there are advantages in that the light scattering ability is small and the transparency of the ink receiving layer is high as compared with pigments not forming secondary particles. If the primary particle size or the secondary particle size of the pigment is too small, it becomes difficult to form voids that contribute to ink absorption, so that the ink absorbability of the ink receiving layer may be inferior. On the other hand, if the primary particle size or the secondary particle size is too large, the transparency of the ink receiving layer is lowered, and it may be difficult to obtain a high print density. On the other hand, if the secondary particle size is too large, not only the gloss of the ink receiving layer is lowered, but also the surface may be roughened or the powder may fall off. In addition, all the primary particle diameters of the pigment as used in the field of this invention are the particle diameters (Martin diameter) observed with the electron microscope (SEM and TEM) (refer to "fine particle handbook", Asakura Shoten, p52). The secondary particle diameter is a particle diameter measured by a dynamic light scattering method.

  Further, in order to obtain an ink-receiving layer having a high ink absorption capacity, the fine pigment preferably has a high pore volume, but the fine pigment suitably used in the present invention has a pore volume of 0.4-2. 5 ml / g. Preferably it is 0.4-2.0 ml / g, More preferably, it is 0.6-1.9 ml / g, Most preferably, it is 0.7-1.8 ml / g. The pore volume is a value obtained using a specific surface area / pore distribution measuring apparatus by a gas adsorption method. In the present invention, the pore volume is the total pore volume of pores having a pore diameter of 100 nm or less. In the fine pigment-based receiving layer, generally, the higher the fine pigment pore volume, the higher the ink absorbency of the coating layer. However, the shrinkage due to the capillary force that occurs during drying after coating also increases. The coating method is liable to cause film formation failure due to cracking and is difficult to put into practical use. However, the ink jet recording material of the method of the present invention does not require such a film formation concern.

  The method for producing these fine pigments is not particularly limited, and as one of the means, there is a method obtained by pulverizing and dispersing a commercially available pigment (several μm) by applying a strong force by mechanical means. That is, it can be obtained by the breaking down method (a method of subdividing the bulk material). Examples of the mechanical means include mechanical methods such as an ultrasonic homogenizer, a pressure homogenizer, a nanomizer, a high-speed rotary mill, a roller mill, a container driving medium mill, a medium stirring mill, a jet mill, and a sand grinder. The fine pigment obtained may be colloidal or slurry. Other preferable methods for producing fine pigments include hydrolysis by metal alkoxides disclosed in JP-A-5-32413 and JP-A-7-76161.

Among the inorganic pigments as described above, silica is particularly preferable because of its relatively large pore volume. Silica includes wet method silica using alkali silicate as a raw material, dry method silica in which a volatile silicon compound such as silicon tetrachloride is decomposed in a flame, and mesoporous silica.
The specific surface area by the "nitrogen adsorption method is described in JP 2001-354408 is at 300m ² / g~1000m ² / g, pore volume is 0.4ml / g~2.0ml / g A liquid in which silica particles are colloidally dispersed is used as a seed solution. After adding alkali to the seed solution, a feed solution consisting of at least one selected from an aqueous solution of active silicate and alkoxysilane is added to the seed solution little by little. to wherein the growing silica particles, specific surface area measured by the nitrogen adsorption method 100m ² / g~400m ² / g, average secondary particle diameter of 20 nm to 300 nm, and a pore volume of 0.5 ml / g Fine silica produced by a method for producing a silica fine particle dispersion in which ~ 2.0 ml / g of silica fine particles are colloidally dispersed is also preferably used. It can be.

The method based on the condensation of active silicic acid disclosed in JP-A-2001-354408 can directly produce fine silica having the above particle diameter and pore volume without using mechanical means, and has a particle size distribution. Since it is narrow, it becomes a coating layer with good transparency and gloss, so that it can be preferably used. Here, the activated silicic acid refers to an aqueous silicic acid solution having a pH of 4 or less obtained by ion exchange treatment of an aqueous alkali metal silicate solution with a hydrogen cation exchange resin, for example. The SiO ₂ concentration is preferably 1 to 6% by mass, more preferably 2 to 5% by mass and an active silicic acid aqueous solution having a pH of 2 to 4. The alkali metal silicate may be a commercially available industrial product, and more preferably a sodium water glass having a SiO ₂ / M ₂ O (where M represents an alkali metal atom) molar ratio of about 2 to 4. It is preferable to use it. As a method for condensing active silicic acid, an aqueous solution of active silicic acid is added dropwise to hot water, or the aqueous solution of active silicic acid is heated to produce seed particles. Before the dispersion liquid precipitates or gels, an alkali is added. to stabilize the seed particles was added and then in terms of SiO ₂ with respect to SiO ₂ 1 mole contained the active silicic acid solution to the seed particle while maintaining the stable state from 0.001 to 0.2 mol / min It is preferable that each primary particle constituting the seed particle is grown by adding at a rate of 5%. The average secondary particle size is 1 μm or less, preferably 20 nm to 800 nm, and most preferably 30 nm to 700 nm. The average secondary particle diameter is a value measured by a particle size meter employing a dynamic light scattering method and analyzed by a cumulant method.

  The pore volume of these various silicas is preferably 0.4 to 2.5 ml / g. On the other hand, there is also silica generally called colloidal silica, which is usually prepared by treating an aqueous alkali silicate salt solution with an ion exchange resin to produce an aqueous silicic acid solution, and then adding alkali to stabilize the aqueous silicic acid solution. This is produced by heating to make a liquid in which fine silica is monodispersed, and gradually adding an aqueous silicic acid solution to grow the silica fine particles. As can be seen from the production method of colloidal silica, the silica particles do not form secondary particles. For this reason, the pore volume is in the range of 0.2 to 0.3 ml / g, which is disadvantageous because the ink absorption amount is small even when used in the ink receiving layer.

  In addition to the fine pigment, which is an essential component, and a hydrophilic resin that forms a hydrogel by irradiating an aqueous solution with active energy rays, a cationic compound that is an ink fixing agent may be mixed in the ink receiving layer. Since a coating solution containing at least a cationic compound is applied to the ink receiving layer in a later step, it is not always necessary to add a cationic compound to the ink receiving layer. However, if the ink receiving layer is cationic, the cationic coating solution is less likely to thicken or aggregate when applied, and promotes penetration of the cationic coating solution into the pores of the ink receiving layer. Therefore, it is preferable. From the viewpoint of water resistance of the resulting receiving layer and prevention of bleeding, it is desirable that the receiving layer after the cation application has a cationic compound in the entire layer centering on the surface layer.

  The type of the cationic compound added to the ink receiving layer is not particularly limited. For example, various cationic resins described above as an example of the additive component to the undercoat layer, or emulsion type cationic resin, polyvalent metal salt Examples include various cationic inorganic salts such as compounds, and these may be used alone or in combination of several kinds. Among various cationic resins, a quaternary ammonium salt type cationic resin having a low discoloration is preferable because it has a stable chemical structure, and a cationic resin containing a diallyldimethylammonium salt structure is particularly preferable. However, various cationic compounds other than these, including a cationic resin having a primary amino group with relatively high discoloration, can also be used depending on the application and addition amount.

When an anionic fine pigment such as silica obtained by the above-mentioned various production methods is used as the fine pigment as the main component of the ink receiving layer, aggregation may occur when these cationic compounds are added. In that case, it is preferable to cationize the fine pigment in advance because shock during mixing is suppressed.
As a cationizing agent for an anionic fine pigment, when the fine pigment is silica, 1) a silane coupling agent having an amino group, 2) a water-soluble cationic resin having an amino group or an ammonium salt, and 3) a polybasic aluminum chloride. And cationizing agents such as polyvalent metal salt compounds. In particular, if the water-soluble cationic resin exemplified as a component added to the ink receiving layer is combined with silica in advance, a polymer-derived binder effect can be expected, which is very suitable.

  The conditions for combining the “water-soluble cationic resin having an amino group or ammonium salt” and silica differ depending on the characteristics of each material. However, the slurry that is agglomerated and thickened by mixing the two is mechanically dispersed and pulverized again. This is achieved by adjusting the secondary particle size of the aggregate to a desired particle size. By passing through this means, the above-mentioned water-soluble cationic resin plunges in a relatively stable state around the silica, so that even when a cationic compound is added separately, compared to the case where it is added to an untreated silica slurry, The shock is greatly reduced. In order to sufficiently obtain this effect, if the amount of the water-soluble cationic resin used for the composite is too small relative to the amount of silica, the silica cannot be stably surrounded. There is a concern that the stability of the slurry and the paint may decrease. On the other hand, if the amount of the water-soluble cationic resin is too large, the ink absorbability is hindered. Specifically, the water-soluble cationic resin is about 0.5 to 30 parts by mass, more preferably 2 to 20 parts by mass with respect to 100 parts by mass of silica. Although it is appropriate, the optimum is different depending on the type and molecular weight of the water-soluble cationic resin, and is not limited thereto.

  Once the aggregated silica and water-soluble cationic resin are mechanically dispersed and pulverized, the average secondary particle size can be dispersed up to about 1 μm with a weak mechanical force such as a homomixer. In order to pulverize the particle diameter to 1 μm or less, it is necessary to apply a stronger mechanical force, and therefore, a pressure dispersion method is desirable. A preferred specific example is a method in which a slurry mixture of raw material particles is continuously passed through an orifice at a high pressure and pulverized at a high pressure, and the treatment pressure is preferably 10 to 350 MPa, more preferably 20 to 300 MPa, and still more preferably. 30 to 200 MPa. Good dispersion or pulverization can be achieved by the above high-pressure pulverization. Furthermore, it is more preferable to use a system in which the slurry mixture that has passed through the orifice at high pressure is dispersed or pulverized by opposing collision. In the method of opposing collision, the dispersion is pressurized and guided to the inlet side, the dispersion is branched into two passages, and the flow path is narrowed by an orifice to accelerate the flow velocity and collide the particles by colliding with each other. Crush. As a material constituting the portion where the dispersion is accelerated or collided, diamond is preferably used for the reason of suppressing the wear of the material.

As the high-pressure pulverizer, a pressure homogenizer, an ultrasonic homogenizer, a microfluidizer, and a nanomizer are used. In particular, a microfluidizer and a nanomizer are preferable as the high-speed collision type homogenizer. The cationized silica thus treated is generally obtained as an aqueous dispersion (slurry or colloidal particles) having a solid content concentration of about 5 to 20% by mass.
Anionic fine pigments other than silica can be cationized in the same manner.

  The hydrophilic resin that forms a hydrogel by irradiating an aqueous solution with active energy rays, which is another main component of the aqueous coating material used in the ink receiving layer of the ink jet recording material of the present invention, is soluble in the aqueous coating material. Alternatively, when active energy rays are irradiated in a dispersed state, a reaction that increases the molecular weight, such as a polymerization reaction or a crosslinking reaction, and a substance that has a property of hydrogelling a paint is particularly useful. It is not limited. As an example, there is a polymer or oligomer having an acryloyl group or a methacryloyl group at a molecular terminal or side chain, which is generally referred to as a photocurable resin, and among them, polyester-based, polyurethane-based, polyepoxy-based, polyether There are systems that can be used. Moreover, the polymer or oligomer which contains several acryloyl group or methacryloyl group in 1 molecule can also be used, and you may mix and use said photocurable polymer or oligomer.

  In addition, when an electron beam is used as the active energy ray, a general hydrophilic resin as exemplified below can be used because a hydrogel is formed by irradiating an aqueous solution with an electron beam. Since these resins are general-purpose products, they can be obtained at a relatively low cost, and since they have a track record of quality and safety as materials for the ink jet receiving layer, they can be most suitably used. Specific examples include fully saponified polyvinyl alcohol, partially saponified polyvinyl alcohol, polyethylene oxide, polyalkylene oxide, polyvinyl pyrrolidone, water-soluble polyvinyl acetal, poly-N-vinylacetamide, polyacrylamide, polyacryloylmorpholine, polyhydroxyalkyl acrylate, poly Acrylic acid, hydroxyethyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, hydroxypropyl cellulose, gelatin, casein, and water-soluble derivatives thereof can be exemplified, but are not limited thereto.

  Water-soluble derivatives include cation-modified products, anion-modified products, derivatives obtained by chemically modifying functional groups such as hydroxyl groups, carboxyl groups, and amino groups by esterification, etherification, amidation, and other side chains by graft polymerization. The polymer which introduce | transduced can be illustrated. Moreover, the said resin or the copolymer containing a water-soluble derivative may be sufficient. Examples of the copolymer include polyvinyl alcohol, polyvinyl pyrrolidone, water-soluble polyvinyl acetal, poly-N-vinylacetamide, polyacrylamide, polyacryloylmorpholine, polyhydroxyethyl acrylate, copolymers made of vinyl monomers such as polyacrylic acid, and the like. Examples thereof include a copolymer containing a monomer other than the monomer constituting the polymer. Moreover, these resins can be used alone or in combination of two or more.

  Among these hydrophilic resins, polyvinyl alcohol or a derivative thereof is most preferably used from the viewpoints of miscibility with fine pigments, coating suitability, and quality of the resulting ink jet recording material. The degree of saponification is not particularly limited and can be appropriately used in the range of 70 to 99.9 mol%. However, if the degree of saponification is too low, the hydrophilicity is lowered, and if too high, there is a possibility of fibrillation, etc. Preferably it is 75-99.9%, More preferably, it is 78-99.8%. Also, the polymerization degree can be appropriately used at 200 to 4500, but if it is too low, the viscosity of the paint may be too low, or cracks may not be suppressed even using an electron beam, and if it is too high The paint viscosity becomes too high, preferably 1000 or more, more preferably 1000-4500.

  Incidentally, a hydrogel is a polymer having a three-dimensional network structure in a state swollen with a solvent containing water as a main component and having no fluidity. The optimum value of the molecular weight of the hydrophilic resin that forms the hydrogel by irradiating the active energy rays used in the method of the present invention is not unclear because the properties differ depending on the type of resin, but if it is too high When mixed with a fine pigment, the coating solution is likely to gel, and even if gelation does not occur, the coating solution may have a high viscosity. On the contrary, even if the molecular weight is too low, the gel strength of the hydrogel obtained by irradiation with active energy rays becomes insufficient, so that the coating film after drying may crack and the effects of the present invention may not be sufficiently obtained. There is. Therefore, as a standard of molecular weight, a typical resin is preferably about 10,000 to 5,000,000, more preferably 5,000 to 1,000,000.

  In order to change the color tone with time after printing, it is also effective to use a resin having a high affinity with the hydrophilic high-boiling solvent contained in the ink alone or in combination. The hydrophilic high-boiling solvents contained in the ink include glycerin, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, diethylene glycol monomethyl ether, 2-pyrrolidone, thiodiglycol, triethylene glycol mono Examples of resins having high affinity with these solvents include butyl ether, 1,5-pentanediol, etc., but include, but are not limited to, polyvinylpyrrolidone, polyacryloylmorpholine, polyhydroxyalkyl acrylate, and hydroxypropylcellulose. Is not to be done.

  The ratio of the fine pigment, which is the main component of the ink receiving layer, and the hydrophilic resin that forms a hydrogel by irradiating the aqueous solution with active energy rays is such that the hydrophilic resin is 1 per 100 parts by mass of the fine pigment. About 100 mass parts is preferable. Since the ink jet recording material of the present invention forms an image mainly by receiving ink in pores formed inside and outside of the pigment, the amount of the hydrophilic resin is minimized from the viewpoint of ink absorption. It is desirable to suppress. Further, since the hydrophilic resin increases the apparent particle diameter of the fine pigment in the ink receiving layer, the hydrophilic resin should be less in the range where cracks do not occur from the viewpoint of the transparency of the ink receiving layer. . For the above reasons, the hydrophilic resin is more preferably contained in an amount of 3 to 30 parts by mass, most preferably 5 to 25 parts by mass with respect to 100 parts by mass of the fine pigment.

  The ink receiving layer of the present invention is porous, but specifically, it is preferably adjusted so that the pore volume is in the range of 0.2 to 2.0 ml / g. It can be adjusted within this range by selecting the pore volume of the fine pigment and by appropriately adjusting the amount of the hydrophilic resin added. When the pore volume is less than 0.2 ml / g, the ink cannot be absorbed unless the coating amount is increased, and the manufacturing cost of the ink jet recording body is increased. A pore volume exceeding 2.0 ml / g is not preferred because the mechanical strength of the ink receiving layer is lowered, and the ink receiving layer is easily scratched, peeled off or cracked. The pore volume of the present invention is the total pore volume of pores having a pore diameter of 100 nm or less.

  The suitable solid content concentration of the water-based paint used in the present invention varies greatly depending on the type of the main pigment, the fine pigment, and the resin, but it is preferably a higher concentration within a range in which the water-based paint can be stably applied. The higher the concentration of the water-based paint, the higher the efficiency of the cross-linking reaction that proceeds by irradiation with active energy rays, and the higher the gel strength can be expected in the coating layer after gelation. It is. In hydrophilic resins that form hydrogels by irradiating active energy rays to the aqueous solution used in the present invention, molecular chains are broken when irradiated with active energy rays without containing moisture. May proceed preferentially and the intended cross-linking reaction may not proceed, but if the same amount or more of water is present in the coating solution relative to the solid content, the cross-linking reaction is almost the same as in an aqueous solution. It is estimated that it will progress. Actually, the higher the concentration of the fine pigment aqueous dispersion suitably used in the present invention, the easier the gelation occurs, so the upper limit of the concentration is often determined in terms of the stability of the aqueous paint. Considering the above points, the solid content concentration of the aqueous paint is preferably 3 to 40% by mass, more preferably 5 to 25% by mass.

  In addition to the main component, without significantly deteriorating the coating properties of the water-based paint, while maintaining the pores necessary for ink absorption, within the range that does not significantly reduce the water resistance of the ink receiving layer, Other components can also be added to the ink receiving layer. These additives themselves may be components that do not form a hydrogel even when an aqueous solution is irradiated with active energy rays.

  For example, an antifoaming agent may be mixed to improve workability during coating, or a surfactant may be added to improve the wettability of the substrate and obtain a uniform ink receiving layer. In order to prevent blocking of the recording medium and to improve the paper passing property of the printer, it is possible to exemplify mixing of starch and synthetic resin particles, but not limited thereto. Various pigments other than the main components can be added to adjust transparency and surface gloss, and light resistance improvers such as UV absorbers and light stabilizers are added to improve the storability of printed images. You can also

  As a method for adding these additives, it may be mixed in advance with a water-based paint, or a coating layer is first formed and then a solution containing the additive is overcoated, sprayed, impregnated, etc. May be added. When the additive is added to the water-based paint in advance, if the paint gels due to the shock of addition, it is also an effective means to re-disperse using mechanical means as in the silica cationization method described above. .

  The ink receiving layer obtained in the present invention can exhibit a sufficient image quality and ink drying property with a single layer structure, but can also have a multilayer structure. In that case, “coating, active energy ray irradiation, drying” may be repeated, the next layer may be applied after application and active energy ray irradiation, or the next layer is applied immediately after application, and the active energy is applied. X-ray irradiation may be performed. Further, multiple layers may be applied simultaneously and active energy ray irradiation may be performed. Further, active energy ray irradiation does not have to be performed for layers that are not necessary.

  If multiple layers are applied by a normal coating method that does not use active energy rays and then try to dry at once, the layers will be disturbed until the drying is completed, and the paint of each layer will be mixed, and the resulting layers will be mixed. In many cases, the coating amount is uneven and the quality is adversely affected. In particular, when the paint has a low viscosity, the coating speed is low, or the coating amount is high, the mixing of each layer is likely to occur. It is desirable to repeat “application and drying”. However, repeating “coating and drying” not only results in poor operability, but also involves the generation of waste paper and an increase in drying load, which inevitably reduces the production efficiency. Furthermore, the adhesive strength between the layers tends to decrease depending on the formulation, and the layers are easily peeled off. In that respect, if the coating material after application is immediately hydrogelated using irradiation of active energy rays, it is possible to obtain a multilayer coating layer that can suppress significant disturbance between layers and that has high adhesion between layers.

  In particular, when applying multiple layers continuously with separate heads, it is possible to perform multi-layer coating in a more stable state by applying an active energy ray irradiation step after lower layer coating and then performing upper layer coating. Is preferred. In addition, in such a multi-layer coating method, the upper layer coating is carried out with the pores in the lower layer filled with water, so the upper layer paint enters the lower layer pores and reduces the pore volume of the lower layer. There is no end. Therefore, it is very suitable as a coating method when the coating layer needs to be porous like the ink jet recording material of the present invention. On the other hand, when performing simultaneous multilayer coating, relatively high-precision multilayer coating is possible compared to continuous coating with separate heads. Can be suppressed, and a sufficiently high-accuracy multilayer coating layer can be obtained.

As a single-layer coating method, a known coating apparatus such as a bar coater, a roll coater, a blade coater, an air knife coater, a gravure coater, a die coater, or a curtain coater can be used, but not limited thereto.
Examples of the apparatus used for multilayer coating include known coating apparatuses such as a slot die coater, a slide die coater, a curtain coater, a knife coater, and a bar coater. In the case of simultaneous coating, a simultaneous multilayer coating apparatus such as a dedicated multilayer slot die coater, multilayer slide die coater, multilayer curtain coater or the like can be suitably used, but is not limited thereto.

The coating amount is preferably about 1 to 60 g / m ² as the mass after drying, and more preferably about 3 to 50 g / m ² . Here, if it is less than 1 g / m ² , ink absorption tends to be insufficient, and if it is more than 60 g / m ² , curling tends to occur and the cost increases, which is not preferable.

  The type of active energy ray used in the present invention is not particularly limited, and examples thereof include α rays, β rays, γ rays, X rays, ultraviolet rays, and electron beams. However, it is preferable to use ultraviolet rays and electron beams which are easy to handle and are widely used. Among them, an electron beam capable of forming a hydrogel with many of general-purpose hydrophilic resins as described above can be most suitably used without adding an initiator or the like to the water-based paint. Moreover, although it is necessary to use the specific hydrophilic resin which has a photoinitiator and an active group for an ultraviolet-ray, the point with cheap irradiation equipment is preferable.

When ultraviolet rays are used as the active energy rays, low-pressure mercury lamps, high-pressure mercury lamps, ultrahigh-pressure mercury lamps, xenon lamps, metal halide lamps, etc. are used as the light source for irradiation, and the intensity is about 5000 to 8000 μW / cm ^2. The ultraviolet ray which has is preferably irradiated. It is preferable to adjust the irradiation amount of ultraviolet rays in a range of about 100 to 2000 mJ / cm ² .

  Moreover, when using ultraviolet rays, it is necessary to mix a photopolymerization initiator in the water-based paint. For example, thioxanthone, benzoin, benzoin alkyl ether xanthone, dimethylxanthone, benzophenone, anthracene, 2,2-diethoxyacetophenone, Light such as benzyl dimethyl ketal, benzyl diphenyl disulfide, anthraquinone, 1-chloroanthraquinone, 2-ethylanthraquinone, 2-ter-butylanthraquinone, N, N'-tetraethyl-4,4-diaminobenzophenone, 1,1-dichloroacetophenone One or more kinds of polymerization initiators are appropriately blended. The blending amount of these photopolymerization initiators should be adjusted in the range of about 0.2 to 10% by mass, more preferably 0.5 to 5% by mass with respect to the hydrophilic resin forming the hydrogel. .

  When an electron beam is used, for example, a scanning method, a curtain beam method, a broad beam method, or the like is adopted as an irradiation method, and an acceleration voltage at the time of irradiation with an electron beam is appropriately about 50 to 300 kV. The amount of electron beam irradiation is preferably adjusted in the range of about 1 to 200 kGy. If it is less than 1 kGy, it is not sufficient to gel the coating layer, and irradiation exceeding 200 kGy is not preferable because it may cause deterioration or discoloration of the substrate or the coating layer.

(Application of a coating solution containing a compound having cationic properties)
In the ink jet recording material of the present invention, a “coating liquid containing a cationic compound” (hereinafter, abbreviated as “cationic coating liquid”) is applied to the porous ink receiving layer. As long as the coating time does not affect the coating surface, the ink receiving layer may be in a wet state before drying or in the middle of drying. As long as the glossy layer can penetrate the porous ink receiving layer without adversely affecting the glossy surface, the glossy layer shown later may be formed.

  The cationic coating solution contains at least a compound having a cationic property and is prepared by dispersing it in a dispersion medium together with other components. Although the kind of compound which has cationic property is not specifically limited, For example, various cationic resin mentioned above is mentioned as an example of the addition component to undercoat. Among them, a water-soluble cationic resin containing a primary amine structure is suitable for addition as an ink fixing agent because of its high ink fixing ability. However, since it originally has a relatively high discoloration property, it is exposed to active energy rays. From the viewpoint of avoiding the concern that the discoloration becomes stronger due to the above, when combined with a porous ink receiving layer obtained by using active energy rays as in the present invention, the primary cationic resin is not added to the ink receiving layer. It is desirable to add to a glossy layer that is not irradiated with active energy rays. Among primary cation resins, from the viewpoint of cation strength and preservability of dye inks, in particular, among structural units obtained by polymerizing monomers selected from ethyleneimine, vinylamine, and allylamine, or 5-membered cyclic amidine structural units, A water-soluble cationic resin that is a polymer containing at least one kind or a derivative thereof is most preferable. Examples of commercially available products include polyethyleneimines such as Epomin P-1000 manufactured by Nippon Shokubai Co., Ltd., allylamine polymers such as PAA-10C manufactured by Nittobo Co., Ltd., and 5-membered ring amidine structures such as Himax SC700M manufactured by Hymo Co., Ltd. However, the present invention is not limited thereto, and any other copolymer or derivative may be used as long as it has a desired structural unit.

  When adding a cationic resin to the cationic coating solution, the optimal molecular weight varies depending on the type of the cationic resin and cannot be defined unconditionally, but the average molecular weight is preferably 500 to 500,000, more preferably 800 to 300,000, Preferably it is 1000-100,000. If the molecular weight is too high, the viscosity of the cationic coating solution will increase and the molecular chain of the cationic resin will be susceptible to steric hindrance, so it will be difficult for the cations after coating to penetrate uniformly into the pores of the porous ink receiving layer. Unsuitable. On the other hand, if the molecular weight is too low, the intended ink fixing ability cannot be obtained sufficiently, which is not preferable.

  In addition, a water-soluble polyvalent metal salt compound or a cationic emulsion may be added as a cationic compound other than these as an ink fixing agent. In particular, water-soluble aluminum compounds exemplified by polyaluminum chloride, aluminum sulfate, aluminum lactate, and aluminum acetate, water-soluble zirconium compounds, and water-soluble titanium compounds are preferably used because of their high ink fixing ability.

  In particular, even if the ink fixing ability cannot be expected, various additives may be added for the purpose of improving the quality of the ink jet recording material. Specifically, fluorescent whitening agents and coloring dyes or pigments for color tone preparation, image preservability improvers such as light stabilizers and UV absorbers, and improvements in the penetration of cationic coating liquids and prevention of repellency Wetting agents and viscosity modifiers are examples of this, but are not limited thereto. These additives may be non-cationic compounds as long as they do not extremely increase the viscosity of the cationic coating solution by mixing.

  An insoluble component may be added to the dispersion medium such as the fine pigment exemplified as the component of the undercoat layer or the ink receiving layer in the cation coating solution, but if these components are mixed in a large amount, the ink absorbability may be lowered. Therefore, the solid content of the cation coating solution is preferably 50% by mass or less, more preferably 30% by mass or less, and most preferably 10% by mass or less.

The optimum concentration of the cation coating solution varies depending on the components to be added, but if it is too low, it will be difficult to add the desired cation amount to the coating layer, and if it is too high, the viscosity of the cation coating solution will increase or the molecular chain of the cation resin will be increased. Is apt to suffer from steric hindrance, so that the cation coating solution is not suitable because it does not easily penetrate into the pores of the porous ink receiving layer. Preferably it is 0.05-60 mass% as solid content concentration, More preferably, it is 0.1-50 mass%, More preferably, it is 0.5-40 mass%, However, It is not limited to this.

In order for the cationic coating solution to uniformly penetrate into the porous ink receiving layer, the viscosity of the coating solution is important. Since the specific viscosity varies greatly depending on the components, concentration, and application conditions, it cannot be generally limited. However, the b-type viscosity at 25 ° C. is preferably 500 mPa · s or less, more preferably 400 mPa · s or less, More preferably, it is 300 mPa · s.

The dispersion medium of the cation coating solution is preferably water, but is not limited thereto. In addition, various organic solvents may be added to enhance the permeability and improve the solubility of the added components. In order to increase the affinity with the ink, the hydrophilic high boiling point solvent contained in the above-mentioned ink is added. May be.
The optimum pH of the cationic coating solution is preferably 1 to 13 from the viewpoint of durability of the coating apparatus. Although it does not specifically limit, since water-soluble cation resin can be added to a free type and high concentration, without raising solid content concentration of a cation coating liquid, it is more preferable that pH is 7 or more.

  In order to allow the cationic coating solution to uniformly penetrate into the porous ink receiving layer, the cationic coating solution may be heated or cooled. The optimum temperature range is preferably 4 to 80 ° C., more preferably 8 to 70 ° C., and most preferably 10 to 60 ° C., but is not limited to this because it varies depending on the components.

The optimum coating amount of the cation coating solution needs to be uniformly applied on the coating layer, and therefore greatly varies depending on the liquid absorbency of the substrate and the coating layer and the moisture content of the coating surface during coating. Thus it can not be flatly defined, preferably 1 to 100 g / ^{m 2,} more preferably 3~80g / ^{m 2} as a coating liquid, more preferably 5 to 60 g / ^{m 2.}
As a method for applying the cationic coating solution, known coating devices exemplified as a coating device for an undercoat layer or an ink receiving layer can be used, but the method is not limited thereto. However, since this coating solution has a lower viscosity than the paint of the undercoat layer and the ink receiving layer, after applying the coating solution on the ink receiving layer or the gloss layer described later using a spraying device such as a spray coater, A technique such as scraping off an excessive coating solution can also be suitably used.

(Glossy layer formation)
In the ink jet recording material of the present invention, a gloss layer containing at least a fine pigment is formed as necessary. In the case where the porous ink-receiving layer can give a silver salt photographic gloss to the cationic coating solution, the cost may be emphasized or the gloss layer may not be formed depending on the application. However, from the viewpoint of gloss of the obtained ink jet recording material, it is preferable to coat it. The glossy layer may be formed either before or after cation coating. When it is formed before cation coating, the ink receiving layer may be formed even after the ink receiving layer has been dried, as long as it does not interfere with coating. May be in a wet state before or during drying, and if formed after cation coating, the wet state before or during drying even after completion of drying of the cation coating solution, as long as the coating is not affected. It may be.

  This gloss layer forming step can be classified into a step of providing a coating liquid layer for a gloss layer, a step of pressing the coating liquid layer with a press roll so as to be in contact with the gloss roll, and a step of drying the coating liquid layer. These steps include, for example, a step of providing a coating liquid layer for a glossy layer with an apparatus as shown in FIG. 1, a step of pressing the coating liquid layer with a press roll so as to contact the glossy roll, and the coating liquid. The step of drying the layer may be performed continuously, or each step may be performed separately in individual equipment. For example, when the step of providing the coating liquid layer is performed separately from the subsequent step of contacting the coating liquid layer with the glossy roll, a known coating facility as exemplified as the method for coating the ink receiving layer is used. I can do it.

  Although the glossing means which performs each process continuously using the apparatus shown in FIG. 1 is illustrated, a means is not limited to this. A sheet comprising a base material 2 provided with a base material or an undercoat layer and a porous ink receiving layer 3 provided thereon, so that the ink receiving layer 3 on the base material 2 is in contact with the gloss roll 5, Guided between the gloss roll 5 and the press roll 6. Here, the coating liquid 4 for forming the glossy layer is supplied onto the ink receiving layer 3 to form a coating liquid pool above the tangent line between the gloss roll 5 and the press roll 6 (gloss layer coating liquid). Providing a layer). And while the coating liquid 4 is in a wet or semi-dry state, the substrate 2 is placed between the gloss roll 5 and the press roll 6 so that the surface supplied with the coating liquid 4 is in contact with the gloss roll 5. Is passed while being pressed (step of pressing the coating liquid layer with a press roll so as to be in contact with the glossy roll). Next, the coating liquid layer 7 is dried with the heated gloss roll 5, or after the coating liquid layer 7 is peeled off from the gloss roll 5, the coating liquid layer 7 is dried with a subsequent dryer 9, or the coating liquid layer 7 is heated. It dries with the gloss roll 5, and dries with the dryer 9 of a post process (process of drying a coating liquid layer). In this way, an ink jet recording body comprising the substrate 2, the ink receiving layer 3, and the gloss layer 8 is manufactured. In addition, after drying with a metal roll, it can also humidify with steam etc. before and after drying with a dryer.

  When the coating liquid layer for the gloss layer is formed in advance using the above-described known coating equipment, the coating liquid is supplied in advance without forming the coating liquid reservoir of the coating liquid 4 and is in a wet state or semi-finished state. You may pass between the gloss roll 5 and the press roll 6 so that the surface in a dry state may contact | connect the gloss roll 5 directly, and the subsequent drying process can be implemented as mentioned above. .

  The coating solution for the gloss layer contains a fine pigment as a main component and contains any other component such as a release agent. The coating solution for forming the gloss layer is prepared by dispersing these components in a dispersion medium.

  Examples of the fine pigment used as the main component of the glossy layer include transparent or white pigments such as colloidal silica, amorphous silica, alumina, aluminum hydroxide, magnesium carbonate, calcium carbonate, kaolin, and calcined kaolin. However, organic pigments can also be used. Among these, colloidal silica, alumina, or amorphous silica is preferable because glossiness is particularly improved. When using colloidal silica or alumina, the average primary particle size is preferably 5 to 100 nm, more preferably 10 to 80 nm. More preferably, it is 20-70 nm. When the average particle diameter is less than 5 nm, the ink absorbability may be reduced, and when the average particle diameter exceeds 100 nm, the transparency tends to decrease and the print density tends to decrease.

  When amorphous silica is used, one having an average primary particle diameter of 5 to 100 nm, more preferably 5 to 40 nm is used. Amorphous silica preferably has an average secondary particle diameter of 1 μm or less, more preferably 10 to 700 nm.

  The above-mentioned various cationic compounds may also be added to the glossy layer. However, if the amount of the cationic compound other than the fine pigment is too large, it is not preferable because it causes a decrease in ink absorbability and a deterioration in releasability. Even when a glossy layer to which no cationic compound is added is provided on the outermost layer after the cationic compound is applied, a high concentration of cations is distributed in the vicinity of the surface layer. Scratch is a sufficiently good level.

  If too much of a cationic compound that easily adheres to the gloss roll such as a water-soluble cationic resin is added to the gloss layer, there is a concern that the ink absorbability decreases and the releasability may deteriorate, but the fine pigment used in the gloss layer is cationic. However, since there are few those concerns, it can be used conveniently. As the cationic colloidal particles, for example, the fine pigment shown in the ink-receiving layer can be used, and selected from vapor-process silica, mesoporous silica, and wet-process silica colloid produced by condensing activated silicic acid. Examples thereof include, but are not limited to, those obtained by cationizing silica by the above-mentioned method, alumina oxide, alumina hydrate, cationic colloidal silica, and the like. In particular, cationic colloidal silica, cationized gas phase method silica, and alumina oxide are preferable because excellent gloss can be obtained.

Although not an essential component, it is preferable to add polyvinyl alcohol to the glossy layer because the surface layer strength is improved. Further, the layer strength is relatively maintained even in a wet state immediately after printing the pigment ink, which is preferable from the viewpoint of scratch resistance of the pigment ink printing portion. This is preferable because the printed portion scratch resistance of the pigment ink obtained by cationic coating is further enhanced. The saponification degree of polyvinyl alcohol is not particularly limited, and can be appropriately used in the range of 70 to 99.9 mol%. However, if the saponification degree is too low, the hydrophilicity is lowered, and if it is too high, there is a risk of fibrillation and the like. Therefore, it is preferably 75 to 99.5%, more preferably 78 to 99%. Further, the polymerization degree can be appropriately used at 200 to 4500. However, if it is too low, there is a high possibility that the ink absorption will be inhibited, and if it is too high, the viscosity of the coating liquid for the glossy layer becomes high, and preferably 300 to 4000. More preferably, it is 500-3000. In addition to normal products, for example, copolymers and derivatives such as cation-modified products can be suitably used.
If the blending number of the polyvinyl alcohol is too large, ink absorption may be reduced, so that the desired balance between the surface layer strength and the ink absorbency is appropriately adjusted. For example, 0.5 to 20 parts by mass, preferably 1 to 15 parts by mass, and more preferably 2 to 10 parts by mass are suitable for 100 parts by mass of the fine pigment as the main component, but the present invention is limited to this. is not.

  If an excessive amount of a hydrophilic resin other than polyvinyl alcohol is added, the ink absorbability may be lowered. However, it can be appropriately used as necessary. For example, polyvinylpyrrolidone and copolymers thereof, cellulose derivatives such as polymethylhydroxycellulose and carboxymethylcellulose, modified starches such as oxidized starch and cationized starch, proteins such as casein, soy protein, synthetic protein, polystyrene resin, polybutadiene Examples thereof include aqueous resins such as resins, polyurethane resins, polyacrylic acid resins, polyvinyl acetate resins, and polyvinyl chloride resins, and copolymers and modified products thereof, which can be used alone or in combination. Of these, styrene / acrylic copolymer emulsions are particularly preferred.

  When using an emulsion type hydrophilic resin, the average particle size is preferably in the range of 20 to 150 nm. If the average particle size is less than 20 nm, the ink absorbency may be reduced, and if it exceeds 150 nm, the glossiness is reduced. There is a case. These glass transition temperatures are preferably in the range of 50 to 150 ° C. When the glass transition temperature is lower than 50 ° C., the gloss layer is excessively formed at the time of drying, and the porosity of the gloss layer is lowered and the ink absorbability may be lowered. When the temperature is higher than 150 ° C., film formation is insufficient, and gloss and strength may be insufficient.

In addition, a release agent can be added to the coating liquid for forming the gloss layer in order to smoothly and stably peel the surface of the formed coating liquid layer from the gloss roll.
Release agents include fatty acids such as stearic acid, oleic acid, and palmitic acid, and salts thereof such as sodium, potassium, calcium, zinc, ammonium, stearic acid amide, ethylene bis stearic acid amide, and methylene bis stearic acid amide. Fatty acid amides such as, aliphatic hydrocarbons such as microcrystalline wax, paraffin wax and polyethylene wax, higher alcohols such as cetyl alcohol and stearyl alcohol, fats and oils such as funnel oil and lecithin, lipids, fluorine-containing surface activity Examples thereof include various surfactants such as agents, and fluorine-based polymers such as tetrafluoroethylene polymer and ethylene-tetrafluoroethylene polymer.

Of these, aliphatic hydrocarbons or derivatives or modified products thereof, fatty acids or salts thereof, and lipids are particularly preferable. Among them, polyethylene wax is used as the aliphatic hydrocarbon, stearic acid or oleic acid is used as the fatty acid, and lipids are used. More preferably, lecithin is used.
In addition to the above, the gloss layer includes various pigments, dispersants and thickeners generally used in the manufacture of coated paper. Various auxiliary agents such as an antifoaming agent, a colorant, a fluorescent dye, an antistatic agent, and an antiseptic may be added as appropriate.

The coating amount of the glossy layer is preferably 0.01 to 10 g / ^{m 2} as dry mass, more preferably 0.1-5 g / ^{m 2,} more preferably 0.3 to 3 g / ^{m 2.} When the coating amount is less than 0.01 g / m ² , it is advantageous in terms of ink absorbability and recording density, but it is difficult to form a sufficient gloss layer, so that the glossiness tends to be low. On the other hand, when the coating amount exceeds 10 g / m ² , the glossiness is easily obtained, but the ink absorbability and the recording density tend to decrease.
In addition, since the gloss layer of the present invention is formed by pressing the gloss layer coating material onto the porous ink receiving layer, a portion of the gloss layer coating material is pressed into the porous ink receiving layer. The boundary between the layer and the ink receiving layer tends to be unclear. Therefore, the thickness of the gloss layer varies greatly depending on the pore state of the ink receiving layer. Therefore, it is difficult to unconditionally define the thickness of the gloss layer, but it is preferably 5 nm to 5 μm, more preferably 10 nm to 3 μm, and most preferably 20 nm to 1 μm. In order to obtain a sufficient gloss on the surface of the coating layer, it is most desirable that the gloss layer coating completely covers the surface of the ink receiving layer while maintaining the pores. It becomes equal to the diameter of the fine pigment used for the glossy layer paint. On the other hand, when the thickness of the glossy layer exceeds 5 μm, it is not preferable because there is a possibility that the ink absorbability and the strength of the coating film may be hindered.

In a general method for producing cast coated paper, the surface of the coating layer in a wet plasticized state is pressed against a heated gloss roll and dried to copy the mirror surface of the gloss roll.
In the present invention, the surface of the coating liquid layer for the glossy layer in a wet state is pressed with a press roll so as to be in contact with the heated gloss roll, and the pigment used in the glossy layer is pressed into the ink receiving layer to give a mirror surface. Therefore, it is not always necessary to completely dry the glossy coating liquid layer. Therefore, the coating solution layer can be separately dried in a drying zone.

  The surface temperature of the gloss roll is preferably in the range of 40 to 130 ° C., more preferably in the range of 70 to 120 ° C., more preferably in the range of 70 to 120 ° C., from the operational properties such as drying conditions, adhesion to the ink receiving layer, and gloss of the gloss layer surface. A range of 110 ° C. is more preferred. When the surface temperature of the gloss roll is less than 40 ° C., the coating strength due to insufficient indentation of the pigment may decrease or the gloss may decrease. When the surface temperature exceeds 130 ° C., the coating may crack. . Further, the gloss roll is preferably a metal roll because it has good heat resistance and excellent specularity.

The material of the press roll is preferably made of a heat resistant resin in order to make the pressurization with the glossy roll as described above more uniform.
The press roll is preferably pressed so that the linear pressure between the gloss roll and the press roll is 50 to 3500 N / cm, more preferably 200 to 3000 N / cm. When the linear pressure between the glossy roll and the press roll is less than 50 N / cm, the linear pressure is difficult to be uniform and glossiness is reduced, or the adhesion of the coating liquid layer to the ink receiving layer is reduced. In the case where it exceeds 3500 N / cm, the ink-absorbing layer may be destroyed due to excessive pressurization of the ink jet recording material, and thus the ink absorbability may be lowered.

  In the present invention, the moisture content of the recording material immediately after peeling from the glossy roll is often higher than its equilibrium moisture content. In the case of a bench scale test, it may be allowed to stand at room temperature and normal humidity to obtain equilibrium moisture. In the case of production with an actual machine, a humidity control / drying device is not necessary when the equilibrium moisture is reached after peeling from the gloss roll and winding with a winder.

  However, when the coating speed is high and the paper moisture is high, a humidity control step having a humidity control device or a drying step having a drying device is required between the gloss roll and the winder. The capacity and specifications of the humidity control or drying device are appropriately set according to the difference between the water content and the equilibrium water content at the time when the recording material is peeled off and the coating speed. When the moisture of the recording medium is adjusted to the equilibrium moisture, the moisture change is preferably as gentle as possible. When the moisture is changed rapidly, there is a possibility that the coating layer is cracked or a strong curl is generated on the recording medium. Therefore, it is best to ensure a sufficient time for conditioning in air at normal temperature and humidity. If the application speed is high or sufficient space cannot be secured due to space constraints, it is better to pass through a box filled with air at normal temperature and low humidity. If it is still insufficient, it is necessary to raise the temperature in the box to make it hot and low in humidity.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. Moreover, unless otherwise indicated, the part and% in an example are a mass part and mass%, respectively.

(Manufacture of base materials)
<< Substrate A >>
Conifer bleached kraft pulp (NBKP) beaten to CSF (JIS P-8121) to 250 ml and hardwood bleached kraft pulp (LBKP) beaten to CSF to 250 ml are mixed at a mass ratio of 2: 8, and the concentration is 0. A 5% pulp slurry was prepared. In this pulp slurry, cationized starch 2.0%, alkyl ketene dimer 0.4%, anionized polyacrylamide resin 0.1% and polyamide polyamine epichlorohydrin resin 0.7% are added to the pulp dry weight. The mixture was sufficiently stirred and dispersed.
The pulp slurry having the above composition was made with a long net machine, and passed through a dryer, a size press, and a machine calendar to produce a base paper having a basis weight of 180 g / m ² and a density of 1.0 g / cm ³ . The size press solution used in the size press step was prepared by mixing carboxyl-modified polyvinyl alcohol and sodium chloride at a mass ratio of 2: 1, adding this to water and dissolving it by heating, and adjusting the concentration to 5%. A total of 25 ml / m ^{2 of} this size press solution was applied to both sides of the paper to obtain a substrate A (air permeability: 1000 seconds).

<< Base material B >>
The following polyolefin resin composition 1 that has been subjected to corona discharge treatment on both sides of the base paper of the substrate A and then mixed and dispersed by a Banbury mixer is applied to the felt surface side of the support A so that the coating amount is 25 g / m ^2. The polyolefin resin composition 2 was applied to the wire side of the support A with a melt extruder (melting temperature: 320 ° C.) having a T-type die so that the coating amount was 20 g / m ^2, and felt. The surface side is cooled and solidified with a mirror surface cooling roll and the wire surface side with a rough surface cooling roll, smoothness (Oken type, J.TAPPI No. 5) is 6000 seconds, and opacity (JIS P8138) is 93%. A base material B coated with resin was obtained.

(Polyolefin resin composition 1)
35 parts long chain low density polyethylene resin (density 0.926 g / cm ³ , melt index 20 g / 10 min), 50 parts low density polyethylene resin (density 0.919 g / cm ³ , melt index 2 g / 10 min), anatase Type titanium dioxide (trade name: A-220, manufactured by Ishihara Sangyo Co., Ltd.) 15 parts, zinc stearate 0.1 part, antioxidant (trade name: Irganox 1010, manufactured by Ciba Geigy) 0.03 parts, ultramarine (trade name) : Aoguchi Ultramarine NO.2000, manufactured by Daiichi Kasei Co., Ltd.) 0.09 part, fluorescent whitening agent (trade name: UVITEX OB, manufactured by Ciba Specialty Chemicals Co., Ltd.) 0.3 part, and polyolefin resin composition 1 It was.

(Polyolefin resin composition 2)
65 parts of high-density polyethylene resin (density 0.954 g / cm ³ , melt index 20 g / 10 minutes) and 35 parts of low-density polyethylene resin (density 0.919 g / cm ³ , melt index 2 g / 10 minutes) are melt mixed. A polyolefin resin composition 2 was obtained.

<< Substrate C >>
Polypropylene synthetic paper (trade name: YUPO GWG-140, manufactured by YUPO Corporation)
<< Base material D >>
100 parts of wood pulp (LBKP; freeness 400 ml CSF), 5 parts of calcined kaolin (trade name: Ancilex, Engelhardt), commercially available sizing agent 0.05 parts, 1.5 parts of sulfuric acid band, wet paper strength agent 0 A paper base material having a basis weight of 140 g / m ² was produced using a papermaking material consisting of .5 parts and 0.75 parts starch.

(Preparation of paint for undercoat layer)
<< Coating a for Undercoat Layer >>
A commercially available gel method silica (trade name: Nipgel AZ600, average primary particle size 10 nm, specific surface area 300 m ² / g, manufactured by Nippon Silica Co., Ltd.) was dispersed and ground with a sand grinder, and then nanomizer (trade name: Nanomizer, Yoshida Machine Industry Co., Ltd.) 10% dispersion liquid having an average secondary particle diameter of 80 nm was prepared after repeated pulverization and dispersion. As a cationic compound, 10 parts of diallyldimethylammonium chloride (trade name: Unisense CP-103, manufactured by Senca Co., Ltd.) is added to the dispersion with respect to 100 parts of the solid content of the silica. Then, pulverization and dispersion were repeated using a nanomizer again to prepare a 10% dispersion liquid having an average secondary particle diameter of 300 nm to obtain cationized silica a.
8% aqueous solution of fully saponified polyvinyl alcohol (trade name: PVA-140H, degree of polymerization = 4000, degree of saponification = 99% or more, manufactured by Kuraray Co., Ltd.) was mixed at a solid content ratio shown below, and the solid content concentration was 15%. Undercoat layer coating material a was prepared.

(Formulation of paint a for undercoat layer)
Cationized silica a: 100 parts Fully saponified polyvinyl alcohol: 15 parts

<< Coating b for undercoat layer >>
The following synthetic amorphous silica and zeolite were each dispersed in water to obtain a 30% aqueous dispersion. Further, a 10% aqueous solution of silyl-modified polyvinyl alcohol shown below was prepared, and sequentially mixed together with the other materials at the following solid content ratio to prepare an undercoat paint b having a solid content concentration of 17%.

(Formulation of paint b for undercoat layer)
Synthetic amorphous silica (trade name: Fine Seal X-60, average secondary particle size 6.0 μm, primary particle size 15 nm, manufactured by Tokuyama Corporation) and 80 parts, zeolite (trade name: Toyo Builder, average particle size 1. 5 parts by weight, 20 parts by silyl-modified polyvinyl alcohol (trade name: R-1130, manufactured by Kuraray Co., Ltd.), polydiallyldimethylammonium chloride polycondensate (trade name: Unisense CP-104, weight average molecular weight 200,000) 15 parts, polydiallyldimethylammonium chloride polycondensate (trade name: Unisense CP-101, weight average molecular weight 20,000, manufactured by Senca), fluorescent dye (trade name: Whitetex BPSH, Sumitomo Chemical Co., Ltd.) 2 parts.

(Preparation of paint for ink receiving layer)
<< Ink-Receptive Layer Coating A >>
Distilled water was mixed with a sodium silicate solution (trade name: No. 3 sodium silicate, manufactured by Tokuyama Corporation) having a SiO ₂ concentration of 30% and a SiO ₂ / Na ₂ O molar ratio of 3.1, and a SiO ₂ concentration of 4.0%. A dilute sodium silicate aqueous solution was prepared. This aqueous solution was passed through a column packed with a hydrogen-type cation exchange resin [trade name: Diaion SK-1BH, manufactured by Mitsubishi Chemical Corporation] to prepare an active silicic acid aqueous solution. The obtained active silicic acid aqueous solution had a SiO ₂ concentration of 4.0% and a pH of 2.9.
In a 5 liter glass reaction vessel equipped with a reflux, a stirrer, and a thermometer, 500 g of distilled water was heated to 100 ° C. While maintaining this hot water at 100 ° C., a total of 450 g of the above active silicic acid aqueous solution was added at a rate of 1.5 g / min to prepare a seed solution. The physical properties of the seed particles in this seed solution were an average secondary particle diameter of 184 nm, a specific surface area of 832 m ² / g, a pore volume of 0.60 ml / g, and a pore diameter of 4 nm.
In the glass reaction vessel, 0.015 mol of ammonia was added to 950 g of the seed solution to stabilize it, and the mixture was heated to 100 ° C. A total of 550 g of the above active silicic acid aqueous solution was added to the seed solution at a rate of 1.5 g / min. After the addition of activated silicic acid was completed, the solution was kept at 100 ° C. and heated to reflux for 9 hours to obtain a fine silica dispersion. The dispersion was a bluish clear solution with a pH of 7.2. The fine silica dispersion had an average secondary particle size of 130 nm, a specific surface area of 257 m ² / g, a pore volume of 1.0 ml / g, and a pore size of 16 nm. This dispersion was concentrated by an evaporator to a silica concentration of 11%.

To 100 parts of this dispersion, 6 parts of an 11% aqueous solution of diallyldimethylammonium chloride polymer (trade name: Unisense CP-103, manufactured by Senka) was added, and a hydraulic ultra-high pressure homogenizer [manufactured by Mizuho Kogyo Co., Ltd., Microfluidizer M110]. -E / H] was repeatedly pulverized and dispersed until the average particle size (average secondary particle size) measured by the following method reached 376 nm, whereby cationized silica A was obtained. When the pore volume of the cationized silica was measured in this state, it was 0.9 ml / g.
The above-mentioned 8% aqueous solution of saponified polyvinyl alcohol was mixed at the solid content ratio shown below to prepare an ink receiving layer coating material A having a solid content concentration of 10%.

(Formulation of paint A for ink receiving layer)
Cationized silica A: 100 parts Fully saponified polyvinyl alcohol: 15 parts

(Measuring method of average secondary particle size of fine pigment)
100 ml of an aqueous dispersion of fine pigment was put into a 500 ml stainless steel cup, and T.K. K. Dispersion treatment (3000 rpm, 5 minutes) was performed using a homodisper to disperse the tertiary particles in the aqueous dispersion. The dispersion after treatment was sufficiently diluted with distilled water to obtain a sample solution, and the average particle size was measured using a laser particle size meter (manufactured by Otsuka Electronics Co., Ltd., LPA3000 / 3100) by a dynamic light scattering method. As the average particle size, a value calculated from an analysis using a cumulant method was used.

<< Ink-Receptive Layer Coating B >>
A commercially available precipitated silica (trade name: Fineseal X-45, average primary particle size 10 nm, specific surface area 280 m <2> / g, average secondary particle size 4.5 [mu] m, manufactured by Tokuyama Corporation) is dispersed and pulverized with a sand grinder and then nanomizer (Product name: Nanomizer, manufactured by Yoshida Kikai Kogyo Co., Ltd.) was used to repeat pulverization and dispersion. After classification, an 11% dispersion having an average secondary particle size of 80 nm was prepared. After adding 6 parts of the above-mentioned diallyldimethylammonium chloride polymer to 100 parts of the solid content of the silica as a cationic compound in the dispersion liquid, causing aggregation of the pigment and thickening of the dispersion liquid, Using a nanomizer again, pulverization and dispersion were repeated to prepare an 11% dispersion having an average secondary particle size of 300 nm to obtain cationized silica B.

The ink receiving layer coating material A having a solid content concentration of 10% was prepared by mixing the 8% aqueous solution of the above-described fully saponified polyvinyl alcohol at a solid content ratio shown below.
(Formulation of paint B for ink receiving layer)
Cationized silica B: 100 parts Fully saponified polyvinyl alcohol: 15 parts

<< Ink-Receptive Layer Coating C >>
An 11% aqueous dispersion of silica (trade name: AEROSIL 300, manufactured by Nippon Aerosil Co., Ltd.) having an average primary particle diameter of 7 nm produced by a gas phase method was dispersed three times with the above-described hydraulic ultrahigh pressure homogenizer. It was 1.6 ml / g when the pore volume of the silica in this aqueous dispersion was measured by said measuring method. The average particle size (average secondary particle size) was 228 nm. 6 parts of an 11% aqueous solution of the above diallyldimethylammonium chloride polymer was added to 100 parts of the dispersion, and the gelled mixture was further dispersed with the same homogenizer to obtain cationized silica C having an average secondary particle diameter of 376 nm. Manufactured. The pore volume of the cationized silica in this state was measured and found to be 1.4 ml / g.

The 8% aqueous solution of the above-mentioned completely saponified polyvinyl alcohol was mixed at the solid content ratio shown below to prepare an ink receiving layer coating material C having a solid content concentration of 10%.
(Prescription of paint C for ink receiving layer)
Cationized silica C: 100 parts Fully saponified polyvinyl alcohol: 15 parts

<< Ink Receiving Layer Paint D >>
A 12% aqueous dispersion of alumina (trade name: AKP-G020, γ-alumina, specific surface area 150 m ² / g, manufactured by Sumitomo Chemical Co., Ltd.) was pulverized and dispersed with a sand grinder, and then dispersed with a hydraulic ultra-high pressure homogenizer. Then, an alumina sol having a pore volume of 0.5 ml / g and an average particle size (average secondary particle size) measured by the above measuring method of 200 nm was prepared.

The above-described 8% aqueous solution of saponified polyvinyl alcohol was mixed at the solid content ratio shown below to prepare an ink receiving layer coating material D having a solid content concentration of 11%.
(Formulation of paint D for ink receiving layer)
Alumina sol: 100 parts Fully saponified polyvinyl alcohol: 7.5 parts

Example 1
The side of the base material B on which the polyolefin resin composition 1 was laminated (the felt surface side of the base paper) was subjected to corona discharge treatment under the following conditions.
(Corona treatment conditions)
High frequency power supply: AGI-021 (output power amount = 1 kW) manufactured by Kasuga Electric Co., Ltd.
Corona electrode: manufactured by Kasuga Electric Co., Ltd., aluminum 5 type 6 mountain (electrode length 500 mm)
Processing speed 15m / min

On this treated surface, the ink receiving layer coating material A was applied in a dry mass so that the coating amount was 25 g / m ² . This was immediately irradiated with an electron beam with an accelerating voltage of 175 kV and an irradiation dose of 30 kGy by an electron beam irradiation apparatus (electrocurtain manufactured by ESI) in a nitrogen gas environment. When the coated surface after irradiation was touched, it was found that the paint became a jelly-like solid and became a hydrogel. This was dried with hot air at 110 ° C. for 10 minutes to form a porous ink receiving layer.

On this treated surface, a 2% aqueous solution (pH = 11.0) of a solid content concentration of PAA-10C (manufactured by Nittobo Co., Ltd., molecular weight of about 15,000, polyallylamine) as a cationic coating solution is applied in a dry mass. After coating to 0.5 g / m ² , hot air drying was performed at 80 ° C. for 2 minutes.

Next, 5 parts of solid release agent (ammonium oleate) was added to 100 parts of the solid content of commercially available colloidal silica (Snowtex OL, pH = 2-4, manufactured by Nissan Chemical Co., Ltd.) on this treated surface. After coating a gloss layer coating with a solid content concentration of 5% and in a wet state, press the chrome-plated mirror drum with a surface temperature of 100 ° C. at a linear pressure of 2000 N / cm to form a gloss layer. The ink jet recording material was obtained by drying with hot air at 110 ° C. for 10 minutes.

Example 2
An ink jet recording material was obtained in the same manner as in Example 1 except that the ink receiving layer coating material A used in Example 1 was replaced with the ink receiving layer coating material B.

Example 3
An ink jet recording material was obtained in the same manner as in Example 1 except that the ink receiving layer coating material A used in Example 1 was replaced with the ink receiving layer coating material C.

Example 4
In Example 3, a 5% solid content cation coating solution (pH = 11.2) was not dried on the ink-receiving layer coating material that had become a hydrogel by electron beam irradiation, and the coating amount was 0. An ink jet recording material was obtained in the same manner as in Example 3, except that the coating was applied at 5 g / m ² and then dried with hot air at 110 ° C. for 10 minutes to obtain a porous ink receiving layer.

Example 5
An ink jet recording material was obtained in the same manner as in Example 3 except that the gloss layer coating was applied without drying after applying the cationic coating solution used in Example 3.

Example 6
5 parts of partially saponified polyvinyl alcohol (trade name: PVA-217, degree of polymerization: 1700, degree of saponification: 87.0-89.0, manufactured by Kuraray Co., Ltd.) with respect to 100 parts of the paint for the gloss layer used in Example 1. An ink jet recording material was obtained in the same manner as in Example 3 except that a paint mixed with 5 parts of a% aqueous solution was used as the paint for the glossy layer.

Example 7
An ink jet recording material was obtained in the same manner as in Example 3 except that no gloss layer was formed.

Example 8
An ink jet recording material was obtained in the same manner as in Example 3 except that the cationic coating solution was replaced with a polyvinylamine aqueous solution having a solid content concentration of 2% (molecular weight: about 20,000, 2% aqueous solution pH = 11.1).

Example 9
Example 3 except that the cationic coating solution was replaced with a polyethyleneimine aqueous solution having a solid content concentration of 2% (Nippon Shokubai Co., Ltd .: Epomin P-1000, molecular weight of about 70,000, 2% aqueous solution pH = 10.6). An ink jet recording material was obtained by this method.

Example 10
Except for replacing the cationic coating solution with a Himax SC-700M aqueous solution (contains 60 mol% of a 5-membered ring amidine structural unit, made by Hymo, molecular weight of about 20,000, 2% aqueous solution pH = 3.9) with a solid content concentration of 2%. Obtained an ink jet recording material in the same manner as in Example 3.

Example 11
Implementation was performed except that the cationic coating solution was replaced with a polyallylamine hydrochloride aqueous solution having a solid content concentration of 2% (manufactured by Nittobo Co., Ltd .: PAA-HCl-3L, molecular weight of about 15,000, 2% aqueous solution pH = 2.3). An ink jet recording material was obtained in the same manner as in Example 3.

Example 12
Inkjet recording was carried out in the same manner as in Example 3 except that the cationic coating solution was replaced with a polyaluminum chloride aqueous solution (manufactured by Taki Chemical Co., Ltd., PAC-250A, 2% aqueous solution pH = 2.8). Got the body.

Example 13
After forming the porous ink receiving layer, an ink jet recording material was obtained in the same manner as in Example 12 except that the gloss layer was formed without applying the cation coating solution, and then the cation coating solution was applied.

Example 14
Gloss layer coating with a solid content concentration of 5%, obtained by adding 5 parts of a release agent (stearyltrimethylammonium chloride) to 100 parts of solid content of commercially available cationized colloidal silica (Snowtex AKL, manufactured by Nissan Chemical Co., Ltd.) An ink jet recording material was obtained in the same manner as in Example 3 except that was used.

Example 15
Addition of 5 parts solid release agent (stearyltrimethylammonium chloride) to 100 parts solid content of commercially available fumed alumina (trade name: PG003, manufactured by CABOT, average particle size: 150 nm, slurry concentration: 40%) An ink jet recording material was obtained in the same manner as in Example 3 except that the gloss layer coating material having a solid content concentration of 5% was used.

Example 16
On the side of the base material B on which the polyolefin resin composition 1 is laminated (the felt surface side of the base paper), the undercoat layer coating a is applied at a dry mass of 5 g / m ² at 110 ° C. Dry with hot air for 5 minutes. An ink receiving layer was formed on the treated surface side in the same manner as in Example 3, and then cation coating and gloss layer formation were performed to obtain an ink jet recording material.

Example 17
An ink jet recording material was obtained in the same manner as in Example 1 except that the ink receiving layer coating material A used in Example 1 was replaced with the ink receiving layer coating material D.

Example 18
Ink reception was carried out in the same manner as in Example 3 except that the base material B used in Example 3 was replaced with the base material A, no corona treatment was performed, and the coating C for the ink receiving layer was applied directly to the felt surface side. After forming the layer, cation coating and gloss layer formation were carried out to obtain an ink jet recording material.

Example 19
An ink jet recording material was obtained in the same manner as in Example 3 except that the base material B used in Example 3 was replaced with the base material C, and the ink-receiving layer coating material C was directly applied to the side subjected to the corona treatment. It was.

Example 20
On the felt surface side of the substrate D, the undercoat layer coating b was applied in a dry mass such that the coating amount was 5 g / m ² and then dried with hot air at 110 ° C. Except that the ink receiving layer was formed using the ink receiving layer coating material D on the treated surface side, cation coating and gloss layer formation were carried out in the same manner as in Example 1 to obtain an ink jet recording material.

Example 21
An 11% aqueous dispersion of silica (trade name: AEROSIL 300, manufactured by Nippon Aerosil Co., Ltd.) having an average primary particle diameter of 7 nm produced by a gas phase method was dispersed three times with the above-described hydraulic ultrahigh pressure homogenizer. An ink jet recording material was produced in the same manner as in Example 3 except that a 10% anionic paint prepared by mixing 15 parts of PVA-140H aqueous solution with 100 parts of this silica sol was used as the ink-receiving layer paint. Got.

Comparative Example 1
After coating the base material B, which has been subjected to corona treatment in the same manner as in Example 3, so that the coating amount C for the ink receiving layer is a dry mass and the coating amount is 25 g / m ² , the electron beam is irradiated. Immediately after drying with hot air at 110 ° C., the coating layer was cracked and peeled off from the substrate, so that the subsequent treatment could not be carried out.

Comparative Example 2
The base B subjected to corona treatment in the same manner as in Example 3 was coated with the temperature-sensitive polymer (polyvinyl alcohol of the ink-receiving layer coating material C) (trade name: ALB-221, manufactured by Asahi Kasei Co., Ltd., temperature point: 24 ° C.). After coating the coating material in place with a dry weight so that the coating amount was 25 g / m ² , it was immediately dried with hot air at 110 ° C. without irradiating with an electron beam. Since it peeled off from the base material, the subsequent treatment could not be performed.

Comparative Example 3
The base B subjected to the corona treatment in the same manner as in Example 3 was subjected to a boric acid aqueous solution having a concentration of 5% in the ink receiving layer coating C to 5 parts boric acid with respect to 100 parts solid content of the cationized silica C. The coating material added in this manner was prepared, and the coating weight was 25 g / m ^{2 in} terms of dry mass, and then immediately dried with hot air at 110 ° C. without irradiation with an electron beam. This coating layer was partially cracked, but a gloss layer was provided thereon in the same manner as in Example 1 to obtain an ink jet recording material.

Comparative Example 4
An ink jet recording material was obtained in the same manner as in Example 3 except that the gloss layer was not applied.

Comparative Example 5
An ink jet recording material was obtained in the same manner as in Example 14 except that the step of applying the cationic coating solution was not carried out and the gloss layer was formed directly on the porous ink receiving layer.

Comparative Example 6
An ink jet recording material was obtained in the same manner as in Example 14 except that 2% water-soluble PVA-217 used in Example 6 was applied instead of the cationic coating solution.

Comparative Example 7
Without carrying out the coating step of the cationic coating solution, directly on the porous ink receiving layer, commercially available colloidal silica (Snowtex 20L, pH = 9.5-11, manufactured by Nissan Chemical Co., Ltd.) with respect to 100 parts solids, The same as in Example 3 except that a gloss layer was formed with a gloss layer coating material having a solid content of 5%, in which 20 parts of a solid content of PAA-10C and 5 parts of a release agent (stearyltrimethylammonium chloride) were added. An ink jet recording material was obtained by this method.

(Evaluation methods)
The ink jet recording materials obtained in Examples and Comparative Examples were evaluated by the following methods. The production conditions of each recording material were shown in Table 1, and the evaluation results were shown in Table 2.

(75 degree gloss)
It measured based on ISO 8254-1 using the gloss meter (GM-26 PRO / AUTO) of Murakami Color Research Laboratory.

(Print density)
EPSON photographic paper recommended setting mode of ink-jet printer PM-G800 (dye ink loading machine) manufactured by Seiko Epson on the entire surface of each sample cut to L size (89 mm x 127 mm) in ISO environment (23 ° C, humidity 50%) Then, 100% black solid was output and dried in the same environment for 24 hours. This printed portion was measured using a black filter of a Macbeth reflection densitometer (manufactured by Macbeth, RD-914). The numbers shown in the table are average values of five measurements.

(Evaluation of the image quality of the recording material in the laminated state with continuous printing)
EPSON photographic paper recommended for Seiko Epson inkjet printer PM-G800 (machine installed with dye ink) in an environment of 30 ° C and 80% humidity in an L size (89 mm x 127 mm) recommended According to JIS-X9204 “High-definition color digital standard image XYZ / SCID”, image identification number: N1 was output in succession two images per sample. After the output of the second sheet, the two printed sheets overlapped on the discharge tray were transferred onto the acrylic plate as they were, and an L-size acrylic plate having a thickness of 5 mm was stacked thereon and allowed to stand. After 24 hours, the recording medium output on the first sheet was taken out and dried in an ISO environment for 24 hours.
The image quality was evaluated in five stages based on the following indices together with a normal image that was output one sample per sample under the same setting conditions in ISO environment and then dried for 24 hours without being laminated.
5 points: There is no blur in the laminated image, and the color tone is almost the same as the normal image and is clear.
4 points: There is no blur in the laminated image. Although the color tone of the light color portion is slightly different from that of a normal image, there is no unnaturalness and the difference is not clear unless the difference is compared.
3 points: There is a slight blur in the laminated image. Compared with a normal image, the color tone is totally different.
2 points: The layered image is very blurred and the color tone is sunk, giving an unnatural impression.
1 point: The laminated image is very blurred and the image is broken. Normal images also lack clarity.

表１及び表２の実施例１〜２１から明らかなように、本発明により染料インク画像の鮮明性に優れ、且つ記録体が印字直後に積層されても画像のにじみや色調変化が生じ難いため連続印刷に好適な銀塩写真調光沢インクジェット記録体が得られた。本発明にインクジェット記録体は、各種基材に、主として多孔質インク受容層を形成する工程と、カチオン塗布液を塗布する工程、光沢層を形成する工程を実施してなるが、下塗り層の形成も含め基材の種類を変えても（実施例３、１６〜２０参照）、カチオン塗布液の成分を変えても（実施例８〜１２参照）、インク受容層の種類を変えても（実施例１〜３、１７、２１参照）、光沢層の成分を変えても（実施例３、６、１４、１５参照）所望の品質が得られた。また、各工程間の乾燥を省いても（実施例４、５参照）、光沢層の形成工程を省いても（実施例７参照）、カチオン塗布の後に実施しても良い。

As apparent from Examples 1 to 21 in Table 1 and Table 2, the present invention is excellent in the clarity of the dye ink image, and even if the recording material is laminated immediately after printing, it is difficult for the image to bleed or change in color tone. A silver salt photographic glossy inkjet recording material suitable for continuous printing was obtained. The ink jet recording material according to the present invention comprises a step of mainly forming a porous ink receiving layer, a step of applying a cationic coating solution, and a step of forming a glossy layer on various substrates. Even if the type of the substrate is changed (see Examples 3 and 16 to 20), the components of the cation coating solution are changed (see Examples 8 to 12), or the type of the ink receiving layer is changed (implementation). In Examples 1-3, 17, and 21), the desired quality was obtained even when the components of the glossy layer were changed (see Examples 3, 6, 14, and 15). Alternatively, the drying between the steps may be omitted (see Examples 4 and 5), the gloss layer forming step may be omitted (see Example 7), or the cation coating may be performed.

  On the other hand, when the ink receiving layer is formed by the coating method as shown in Comparative Examples 1 to 3, the coating layer peels off due to cracking (see Comparative Examples 1 and 2), or the coating layer does not peel off, but in the coating layer. Since the crack defect could not be completely suppressed, the appearance deteriorated (see Comparative Example 3). Further, when the glossy layer is not formed on the ink receiving layer of the present invention, the gloss of the recording medium is not only slightly insufficient as a silver salt photograph substitute, but also the image at the time of lamination is blurred (see Comparative Example 4). . Even if a glossy layer is applied, gloss is greatly improved, but bleeding at the time of lamination is not eliminated (see Comparative Example 5), and bleeding is also improved by applying a non-cationic coating solution instead of cationic coating. (See Comparative Example 6). When a cationic resin was added to the glossy layer, the bleeding of the laminated image was improved, but the performance of the ink jet recording material of the present invention was not reached (see Comparative Example 7).

A part of the coating apparatus will be described.

Explanation of symbols

1: Inkjet recording body 2: Base material 3: Ink receiving layer 4: Coating liquid 5: Gloss roll 6: Press roll 7: Coating liquid layer 8: Gloss layer 9: Dryer

Claims (12)

On the substrate, an aqueous paint containing (a) a fine pigment and a hydrophilic resin that forms a hydrogel by irradiating an aqueous solution with active energy rays is applied, and then the active energy rays are applied to the aqueous paint. Porous, characterized in that it comprises a step a for hydrogelating a paint coating layer, and a step b for applying a coating solution containing at least a cationic compound on the layer formed by (b) step a. For producing an ink jet recording material having a quality ink receiving layer. On the substrate, an aqueous paint containing (a) a fine pigment and a hydrophilic resin that forms a hydrogel by irradiating an aqueous solution with active energy rays is applied, and then the active energy rays are applied to the aqueous paint. Step a for hydrogelating the paint coating layer, Step b for applying a coating solution containing at least a cationic compound on the layer formed by Step (b), and Step (c) formed by Step b A coating solution for a glossy layer containing at least a fine pigment is applied onto the formed layer, then pressed with a press roll so that the coating solution layer for the glossy layer is in contact with the glossy roll, and the coating solution layer is dried. A method for producing an ink jet recording material having a porous ink receiving layer, comprising the step c of forming a glossy layer. On the substrate, an aqueous paint containing (a) a fine pigment and a hydrophilic resin that forms a hydrogel by irradiating an aqueous solution with active energy rays is applied, and then the active energy rays are applied to the aqueous paint. Step (a) for hydrogelating the paint coating layer and (d) a coating solution for gloss layer containing at least a fine pigment is applied on the layer formed by step a, and then the coating solution layer for gloss layer is Step d for pressing the press roll so as to contact the gloss roll, drying the coating liquid layer to form a gloss layer, and (e) containing at least a cationic compound on the layer formed by step d. A method for producing an ink jet recording body having a porous ink receiving layer, comprising a step e of applying a coating liquid. The method for producing an ink jet recording material according to any one of claims 1 to 3, wherein the base material is a base material having an undercoat layer containing a pigment and a binder at least on the side on which the ink receiving layer is formed. . The method for producing an ink jet recording material according to any one of claims 1 to 4, wherein the cationic compound contained in the coating liquid of the step b or step e is a water-soluble cationic resin. 6. The ink jet recording material according to claim 5, wherein the water-soluble cationic resin which is a compound having a cationic property is a polymer containing at least one of the following (X) and (Y) or a derivative thereof. Production method.
(X) a monomer selected from ethyleneimine, vinylamine, and allylamine;
Polymerized structural unit (Y) 5-membered ring amidine structural unit The method for producing an ink jet recording material according to any one of claims 5 to 6, wherein the water-soluble cationic resin which is the cationic compound has an average molecular weight of 1,000 to 100,000. The method for producing an ink jet recording material according to any one of claims 1 to 4, wherein the cationic compound contained in the coating liquid of the step b or step e is a polyvalent metal salt compound. The method for producing an ink jet recording material according to any one of claims 1 to 8, wherein the pH of the coating liquid containing the cationic compound in step b or step e is 7 or more. 10. The fine pigment contained in the water-based paint serving as the ink receiving layer is silica having an average particle diameter of 500 nm or less and cationized by complexing with a water-soluble cationic resin. The manufacturing method of the inkjet recording body in any one. An ink jet recording material having a porous ink receiving layer on a substrate, which is produced by the method according to claim 1. An aqueous coating layer containing a hydrophilic resin and a fine pigment is hydrogelated by active energy ray irradiation on the substrate, and has a porous ink receiving layer in which a cationic compound is attached to the surface of the pores Inkjet recording body.

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