JP4834709B2 - Postcard for inkjet recording - Google Patents

Description

  The present invention relates to a postcard for inkjet recording. In addition, the present invention relates to a postcard for ink jet recording which has good castability, no bleeding after ink jet printer printing, high printing strength, and excellent economic efficiency.

  In recent years, as the ink jet recording system has spread to the general public, it has been adopted for postcards. Various postcards for inkjet recording have been proposed (see, for example, Patent Document 1, Patent Document 2, Patent Document 3, or Patent Document 4).

  Postcards usually have a postal code frame, a stamp frame, or a lottery number for New Year's postcards with New Year's cards printed on the address side. There is an increasing demand for good inking properties.

  Moreover, the literature using the specific filler or the literature which paid its attention to the disaggregation freeness of the pulp to be used is disclosed (for example, refer patent document 5 or patent document 6).

JP-A-9-143900 JP 2003-127528 A Japanese Patent No. 3253259 Patent No. 3996106 JP 2001-260527 A JP 2006-289813 A

  However, in general, a method using polyvinyl alcohol having a high covering property is used as a means for increasing the surface strength, but the air permeability becomes high, and a minute defect called “pit” is generated during the casting process, which adversely affects the quality. Bring. Further, starch generally used as a means for increasing the surface strength has a limit in improving the printing durability even if the coating amount is increased.

  Further, if the coating amount of the ink recording layer is not appropriate, the image when ink jet printing is performed is not only impaired, but the cost is increased, and the operability of the casting process and the printing on the address surface are adversely affected.

  Furthermore, with the widespread use of inkjet printers and higher resolutions, photographic-like high-definition images are desired on the so-called communication side.

  As described above, there are a wide variety of characteristics required for postcards, and the conventional techniques such as Patent Documents 1 to 4 have not sufficiently satisfied these characteristics.

  In addition, with the technique disclosed in Patent Document 5 or Patent Document 6, the printing strength of the non-coated surface is poor and printing cannot be performed in practice.

  Therefore, the object of the present invention is that the pit is not generated in the casting process, the productivity is high, and the operability is stable (hereinafter simply referred to as “casting aptitude”), and the bleeding after printing on the ink jet printer is good. It is to provide a postcard for ink jet recording which has high printing strength and is economically advantageous. In the present invention, “casting” refers to a recording medium in which a coating layer in a wet state is pressure-bonded to a heated mirror surface, the mirror surface is transferred to the surface of the coating layer, and moisture is removed from the coating layer by drying. This is a process for imparting gloss to the surface.

As a result of intensive studies, the present inventors have found that an ink jet recording postcard having the following configuration has good castability, no bleeding after ink jet printer printing, high printing strength, and excellent economic efficiency. It was. That is, the postcard for inkjet recording according to the present invention is an ink of at least one layer comprising a paper support, a pigment mainly composed of synthetic amorphous silica, and an adhesive resin formed on the paper support. a recording layer, possess a gloss layer formed on the ink recording layer, wherein the gloss layer is an ink jet recording postcard formed by a cast coating method, (1) the paper support is wood pulp And the freeness (CSF) is 500 ml or more and 700 ml or less, and either a single aluminosilicate or calcined clay or a mixture of aluminosilicate and calcined clay is used in the paper support. 1 to 10% by mass based on the total mass of the support, (2) Polyacrylamide per one side only on both sides of the paper support or the opposite side of the recording layer Is coated in a range of燥塗coating amount 0.5 to 2.5 g / ^{m 2,} and said the (3) the ink recording layer, dry coating weight of 3 to 15 g / ^{m 2,} To do. The ink jet recording postcard according to the present invention comprises at least one layer of ink comprising a paper support, a pigment mainly composed of synthetic amorphous silica, and an adhesive resin formed on the paper support. An ink jet recording postcard having a recording layer and a gloss layer formed on the ink recording layer, wherein the gloss layer is formed by a cast coating method, and (1) the paper support is made of wood pulp And the freeness (CSF) is 500 ml or more and 700 ml or less, and either a single aluminosilicate or calcined clay or a mixture of aluminosilicate and calcined clay is used in the paper support. 1 to 10% by mass based on the total mass of the support, and (2) polyvinyl alcohol and a surface sizing agent only on both sides of the paper support or the opposite side of the recording layer Size liquid that has use is coated in a range of dry coating amount 0.2 to 1.5 g / ^{m 2} per surface (3) the ink recording layer, dry coating weight is 3 to 15 g / ^{m 2} (4) The surface sizing agent may be an olefin sizing agent or an alkenyl succinic anhydride used alone or a mixture thereof.

  The postcard for inkjet recording according to the present invention includes a case where the air resistance (Gurley) measured according to JIS P 8117: 1998 after providing the ink recording layer is 50 seconds or more and 100 seconds or less. At this time, generation of pits is suppressed.

  In the postcard for inkjet recording according to the present invention, the mixing ratio of polyvinyl alcohol to be coated on the surface of the paper support and the surface sizing agent is polyvinyl alcohol: surface sizing agent = 1: (0.01 to 0.20). Preferably there is. Air permeability resistance is likely to decrease and contamination is less likely to occur during operation.

  The postcard for ink-jet recording of the present invention has good castability, no bleeding after printing with an ink-jet printer, excellent printing strength, and economical performance.

  Hereinafter, although an embodiment is shown and explained in detail about the present invention, the present invention is limited to these descriptions and is not interpreted. In addition, the embodiment may be modified as long as the effects of the invention are achieved.

  The ink jet recording postcard according to this embodiment includes (1) a paper support, (2) formed on the paper support, and includes at least one pigment mainly composed of synthetic amorphous silica and an adhesive resin. An ink recording layer, and (3) a glossy layer formed on the ink recording layer. These three configurations will be described in order.

(Paper support)
The paper support is mainly composed of wood pulp, but the pulp used for the base paper of the paper support of the present invention (hereinafter sometimes simply referred to as “base paper”) includes hardwood bleached sulfite. Pulp (LBSP), hardwood bleached kraft pulp (LBKP), softwood bleached sulfite pulp (NBSP), softwood bleached kraft pulp (NBKP), deinked pulp and the like are advantageously used. Moreover, you may use a non-wood pulp, a synthetic pulp, or a synthetic fiber other than a wood pulp as needed.

  The pulp disintegration freezing degree (also referred to as freeness (CSF)) used for the paper support of the present invention is 500 ml or more, preferably 520 ml or more, more preferably 550 ml or more, and 700 ml or less, preferably 650 ml or less. More preferably, it is 600 ml or less. If it is less than 500 ml, the suitability of the ink jet printer and the air permeability after coating the ink recording layer are deteriorated. On the other hand, when the amount exceeds 700 ml, the fiber-to-fiber bond is weakened, and the paper strength is reduced. The disaggregation freeness in the present invention is determined by using a Tappi disaggregator (JIS P 8209: 1994 “Preparation method for pulp paper for hand testing of paper (discontinued: November 20, 1998)”) as a solid content concentration. It is obtained by measuring a slurry adjusted to 1% by mass and adjusted to disaggregation for 25 minutes with a Canadian standard freeness tester (specified in JIS P 8121: 1995 “Pulp Freeness Test Method”).

  In the present invention, either aluminosilicate or calcined clay as a filler in the paper support is 1 to 10% by weight, preferably 2 to 9% by weight, more preferably 4 to 4% by weight based on the total weight of the paper support. 8% by mass is contained.

  Aluminosilicates are siloxanes: Si-O-Si groups arranged in a lattice, and aluminosilicates: Si-O-Al groups are partially arranged at the same positions in the core of the lattice. is there. On the surface of aluminosilicate, a silanol group: Si-OH is found as well as Na-O- group and zeolite-bound soda, and the arrangement of alumina and soda on the surface changes slightly, It has become a complex and highly reactive pigment. The influence of the aluminosilicate on the paper quality of the paper support increases the specific volume and improves the air permeability.

The aluminosilicate has an average particle diameter of 2 to 30 μm, preferably 5 to 20 μm, more preferably 7 to 15 μm, and a BET specific surface area of 20 to 80 m ² / g, preferably 30 to 70 m ² / g. Preferably it is 35-60 m < ² > / g. Here, the average particle diameter used was a value measured with a laser particle size measuring instrument (device used: Microtrac HRA manufactured by HONEYWELL). As the BET specific surface area, a value obtained by a nitrogen adsorption / desorption method (device used: Micrometrics Flowsorb II2300 manufactured by Shimadzu Corporation) was used.

  The calcined clay is obtained by artificially calcining the clay at 650 to 700 ° C., and becomes a light sintered and agglomerated state due to the calcining process, and therefore there are many voids. As a result, regarding the influence on the paper quality of the paper support, it is assumed that the same effect as that of the aluminosilicate is given.

The calcined clay has an average particle size of 0.1 to 10 μm, preferably 0.3 to 5 μm, more preferably 0.5 to 3.5 μm, and a BET specific surface area of ² to 50 m ² / g, preferably 5 30 m ² / g, more preferably 10 to 20 m ² / g. As the average particle size, a value measured with a laser particle size measuring device (device used: Microtrac HRA manufactured by HONEYWELL) was used. As the BET specific surface area, a value obtained by a nitrogen adsorption / desorption method (device used: Micrometrics Flowsorb II2300 manufactured by Shimadzu Corporation) was used.

  The paper support used in the postcard for inkjet recording of the present invention is a mixture of aluminosilicate and calcined clay as a filler, 1 to 10% by weight, preferably 2 to 9% by weight, based on the total weight of the paper support. More preferably, you may make it contain 4-8 mass%. Here, the blending ratio (mass ratio) of the aluminosilicate and the calcined clay in the mixed product is preferably aluminosilicate: calcined clay = 90: 10 to 1:99, and more preferably 50:50 to 1:99.

  If the content of any one of aluminosilicate or calcined clay or a mixture of aluminosilicate and calcined clay is less than 1% by mass, the suitability of the ink jet printer according to the present invention and the air permeability after coating of the ink recording layer are poor. It becomes sufficient, and the effect on cast suitability is not obtained. On the other hand, when it exceeds 10% by mass, not only the paper strength of the paper support is lowered and there is an operational problem, but also paper dust is generated due to a reduction in surface strength.

  The content of any one of aluminosilicate and calcined clay or a mixture of aluminosilicate and calcined clay in the paper support in the present invention is JIS P 8251: 2003 “paper, paperboard and pulp-ash content. The ash content is determined by “Test method—525 ° C. combustion method”.

In the present invention, the polyacrylamide is applied in a range of 0.5 to 2.5 g / m ² on one side of the paper support or the opposite side of the surface on which the recording layer is formed. . In addition, a dry coating amount per side of 0.2 to 1.5 g / m of a sizing liquid in which polyvinyl alcohol and a surface sizing agent are used in combination only on both surfaces of the paper support or on the surface opposite to the surface on which the recording layer is formed. You may apply in the range of ² .

  Polyacrylamide is not limited to ionicity, polymerization degree, carboxyl group content and the like. Polyvinyl alcohol is not limited to the degree of saponification, the degree of polymerization, the modification method, and the like.

The surface sizing agent used in combination with polyvinyl alcohol is at least one selected from olefin sizing agents and alkenyl succinic anhydrides (ASA) . The surface sizing agents other than these two types cause problems such as a low effect of reducing the air resistance after coating of the ink recording layer, or poor liquid stability and operational problems. The mixing ratio of polyvinyl alcohol and surface sizing agent is preferably polyvinyl alcohol: surface sizing agent = 1: (0.01-0.20), and 1: (0.02-0.15). Is more preferable. If the surface sizing agent ratio is less than 0.01 with respect to polyvinyl alcohol 1, the effect of lowering the air resistance after coating the ink recording layer is thin. Is likely to occur, which is disadvantageous in terms of cost.

  In the present invention, the air permeability resistance (Gurley) (hereinafter also referred to as “air permeability” or “Gurley air permeability”) after the ink recording layer is provided on the paper support is 100 seconds. Desirably, it is preferably 90 seconds or shorter, more preferably 80 seconds or shorter. If it exceeds 100 seconds, pits are generated more frequently during the casting process, which adversely affects quality. The air permeability is desirably 50 seconds or more. In order to suppress the occurrence of pits, it is necessary to reduce the production speed, which hinders productivity. As for the control method of air permeability, (1) the wood pulp freeness (CSF) used for the paper support according to the present invention is changed within a range of 500 ml or more and 700 ml or less, (2) in the paper support. At least one kind of aluminosilicate or calcined clay or a mixture of aluminosilicate and calcined clay is changed within a range of 1 to 10% by mass with respect to the mass of the paper support as a whole. A typical means is to apply a size press solution of, but is not limited to these means.

  In the present embodiment, fillers other than aluminosilicate or calcined clay may be added to the extent that the effects of the invention are not impaired. As the filler that may be added, one or more kinds of known fillers such as hydrated silicic acid, white carbon, talc, kaolin, clay, calcium carbonate, titanium oxide, synthetic resin filler and the like can be used in combination. The addition amount is preferably 100 parts by mass or less with respect to 100 parts by mass of any one of aluminosilicate and calcined clay or a mixture of aluminosilicate and calcined clay.

  The pulp slurry beaten to a predetermined freeness is made into a single layer or multiple layers by a paper machine such as a long net paper machine, a twin wire paper machine or a circular net paper machine. At this time, it is possible to add various additives such as a dispersion aid, a dry paper strength enhancer, a sizing agent, and a fixing agent as needed without impairing the effects of the invention. Furthermore, if necessary, pH adjusting agents, dyes, colored pigments, fluorescent brightening agents, and the like can be added.

In the present invention, the coating liquid is applied to the base paper made as described above, but the sizing agent of polyacrylamide, polyvinyl alcohol and olefin sizing agent, alkenyl succinic anhydride (ASA) or the like is used. You may add materials other than the size liquid which used together with the surface sizing agent to such an extent that the effect of invention is not impaired. As materials that can be added and mixed, known materials such as oxidized starch, self-modified starch and urea-phosphorylated starch can be used. If necessary, pH adjusting agents, dyes, colored pigments, fluorescent brighteners, and the like can be added. Other than the surface sizing agent specified by the present invention ( at least one of olefin-based sizing agent or alkenyl succinic anhydride (ASA)) may be added to such an extent that the effects of the invention are not impaired. For example, it can be mentioned up such modified wax-based sizing agents.

The coating amount of the sizing liquid on the base paper is preferably such that the dry coating amount of polyacrylamide on one side is 0.5 to 2.5 g / m ² , particularly 1.0 to 2.0 g / m ^2. The range of is preferable. Sizing solution using a combination of polyvinyl alcohol and a surface sizing agent is preferably in a range dried coated amount of 0.2 to 1.5 g / ^{m 2} per surface, particularly from 0.5 to 1.0 g / ^{m 2} Is preferred.

  As the size liquid coating method, a conventional size press, a gate roll size press, a film transfer type size press, an air knife coater, a rod coater, or the like can be used.

  Moreover, it is good also as a coating only for an address surface side using a film transfer system size press, an air knife coater, a rod coater etc. as needed.

  The coated surface of the size press is only the opposite surface of the paper support or the surface on which the recording layer is formed. Since the surface on which the recording layer is formed does not need a surface strength that can withstand printing, the application of a size press can be omitted.

  An ink recording layer may be provided directly on the base paper (paper support) produced in this way, but for the purpose of smoothing the surface of the base paper in advance, a machine calendar, soft calendar, thermal calendar, raster press, etc. It is preferable to perform the process.

(Ink recording layer)
As the pigment used in the ink recording layer, synthetic amorphous silica is mainly used (preferably, 80% by mass or more based on the total pigment), but the following pigments can be used in combination so as not to affect the quality. . For example, colloidal silica, colloidal alumina, pseudoboehmite, aluminum hydroxide, alumina, lithopone, hydrous halloysite, magnesium carbonate, magnesium hydroxide, aluminum silicate, diatomaceous earth, calcium silicate, magnesium silicate, light calcium carbonate, heavy calcium carbonate, In addition to white inorganic pigments such as kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, and satin white, styrene plastic pigments, acrylic plastic pigments, polyethylene, microcapsules, urea resins, Organic pigments such as melamine resins can also be used.

  The following adhesive resin (binder) is used for the ink recording layer of the present invention. For example, polyvinyl alcohol, polyethylene vinyl acetate, modified polyvinyl alcohol, cellulose derivatives such as hydroxyethyl cellulose, carboxymethyl cellulose, polyvinyl pyrrolidone, polyvinyl pyridine, polyacrylamide, polyethylene oxide, polypropylene oxide, starch, modified starch, polyacrylic acid, polyacrylic acid Water-soluble binders such as soda, sodium alginate, polystyrene sulfonate, casein, gelatin, terpene, polyethylene, polypropylene, polyisobutylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyvinyl acetal, polyacrylamide, polyacryl Ethyl acetate, polymethyl methacrylate, polyacrylonitrile, polytetrafur Polyethylene, polyvinylidene fluoride, polybutadiene, polyisoprene, polychloroprene, nylon, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyacetal, polybischloromethyloxacyclobutane, polyphenylene oxide, polysulfone, poly-p-xylylene, polyimide, poly Benzimidazole, phenol resin, urea resin, melamine resin, epoxy resin, alkyd resin, unsaturated polyester resin, diallyl phthalate resin, styrene-butadiene copolymer, modified styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, methyl Methacrylate-butadiene copolymer, acrylic ester-methacrylic ester copolymer, vinyl acetate-maleic acid ester Copolymers, vinyl acetate - acrylic copolymer, ethylene - vinyl acetate - can be exemplified emulsion binder, or a urethane resin binder such as an acrylic copolymer. The degree of polymerization and saponification, glass transition temperature (Tg), and minimum film forming temperature (MFT) of these binders are not limited. Moreover, you may add a crosslinkable functional group in these molecular chains.

  In the ink recording layer, in order to improve the fixability and color developability of the inkjet ink, it is preferable to use the following ink fixing agent mainly composed of a cationic polymer. Such cationic polymers include polyethyleneimine, epichlorohydrin-modified polyalkylamine, polyamine polyamide epichlorohydrin, dimethylamine ammonia epichlorohydrin, polyvinylbenzyltrimethylammonium halide, polydiacryldimethylammonium halide, polydimethylaminoethyl methacrylate hydrochloride, polyvinylpyridium. Halide, cationic polyacrylamide, cationic polystyrene copolymer, diallyldimethylammonium chloride polymer, diallyldimethylammonium chloride sulfur dioxide copolymer, diallyldimethylammonium chloride amide copolymer, dicyandiamide formalin polycondensate, dicyandiamide diethylenetriamine polycondensation , Polyallylamine , Polyallylamine hydrochloride, polyacrylamide resin, polyamide epoxy resin, melamine resin acid colloid, urea resin, cation-modified polyvinyl alcohol, amino acid type amphoteric surfactant, betaine type compound, quaternary ammonium salt, polyamine, etc. It is done.

  In the ink recording layer coating liquid, a dispersant, an antifoaming agent, a pH adjusting agent, a wetting agent, a water retention agent, a thickening agent, a crosslinking agent, a release agent, a preservative, a softening agent, a wax, Select the appropriate antistatic agent, antistatic agent, sizing agent, waterproofing agent, plasticizer, fluorescent whitening agent, coloring pigment, coloring dye, reducing agent, ultraviolet absorber, antioxidant, fragrance, deodorant, etc. Can be added. Further, the place and the method of adding these are not limited, for example, in the pigment slurry or in the binder.

  The ink recording layer is formed by a general coating machine, for example, a blade coater, a roll coater, an air knife coater, a rod coater, a lip coater, a curtain coater, a spray coater, a die coater, a champless coater, a chip blade coater, etc. Or apply on-machine.

The ink recording layer coating liquid preferably has a dry coating amount of 3 to 15 g / m ² on the communication surface, particularly preferably in the range of 5 to 10 g / m ² . When the dry coating amount is less than 3 g / m ² , not only the ink jet printing quality is deteriorated, but also the binder migration occurs as a result of the coating liquid for obtaining the glossy layer sinking during the casting process. The required quality such as glossiness cannot be obtained. Also, if the dry coating amount exceeds 15 g / m ² , the coating layer may fall off, causing troubles including during the casting process, and even when printing on the address side, powder falling off the edge of the postcard paper Cause. Naturally, since it costs chemicals, it is disadvantageous in terms of cost.

(Glossy layer)
As a method for forming a glossy layer on the ink recording layer, a cast coating method may be mentioned. As the cast coating method, a known method such as a wet method, a rewetting method, or a gelling method may be appropriately used. The coating method of the coating liquid for obtaining the gloss layer is not particularly limited, and is a general coating method, for example, blade coater, roll coater, reverse roll coater, air knife coater, die coater, bar coater, Coating methods such as a gravure coater, curtain coater, chambrex coater, lip coater, and rod coater can be employed.

  As a white pigment used as a coating liquid (gloss layer coating liquid) for forming a glossy layer, one or more known white pigments can be used. For example, light calcium carbonate, heavy calcium carbonate, magnesium carbonate, magnesium hydroxide, kaolin, calcined kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc carbonate, zinc sulfide, satin white, aluminum silicate, diatomaceous earth Examples thereof include inorganic pigments such as earth, calcium silicate, magnesium silicate, lithium silicate, synthetic silica, colloidal silica, alumina, colloidal alumina, pseudoboehmite, aluminum hydroxide, ritbon, and zeolite, and organic pigments such as plastic pigment.

  As the binder to be added to the gloss layer coating liquid, a resin having high adhesive strength and not causing blocking between postcard papers is preferable, and emulsion, latex, natural polymer, and the like can be used alone or in combination. Examples of such binder include styrene-butadiene copolymer, modified styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, methyl methacrylate-butadiene copolymer, chloroprene latex, acrylate ester and methacrylate ester. Polymer or copolymer, ethylene vinyl acetate copolymer, vinyl acetate-maleic acid ester copolymer, acrylic-vinyl acetate copolymer, vinyl acetate copolymer, polyurethane resin, unsaturated polyester resin, starch, oxidized starch , Esterified starch, enzyme-modified starch, cationized starch, cellulose derivatives such as polyvinyl alcohol, hydroxyethyl cellulose, carboxymethyl cellulose, polyacrylamides, polyvinyl pyridine, polyethylene oxa , Polyvinyl pyrrolidone, polyvinyl acetal, polyvinyl butyral, casein, sodium alginate, polystyrene sulfonate soda, starch-acrylonitrile graft polymer hydrolyzate, sulfonated chitin, carboxylated chitin and chitosan, and derivatives thereof. it can.

  It is preferable that the addition amount of the binder in the coating liquid composition for glossy layers is 20-60 mass parts with respect to 100 mass parts of pigments, and 30-50 mass parts is more preferable. When the binder is less than 20 parts by mass with respect to 100 parts by mass of the pigment, the strength of the coating layer is weak, and problems such as falling off of the coating layer and powder falling off easily occur. Moreover, since coating property will deteriorate when it exceeds 60 mass parts, the characteristic of a pigment is easy to be obstructed by coat | covering a pigment.

For the glossy layer coating liquid, dispersants, antifoaming agents, mold release agents, pH adjusters, lubricants, water retention agents, thickeners, water resistance agents, preservatives, surfactants, UV rays are used as necessary. Absorbers, fluorescent brighteners, colored pigments, colored dyes, flow improvers and the like can be appropriately selected and added. A glossy layer can be provided by providing the coating layer for the glossy layer coating solution thus prepared by a cast coating method. At this time, the coating amount is applied such that the dry coating amount per side is preferably 3 to 15 g / m ² , more preferably 4 to 10 g / m ² . When the coating amount is 3 g / m ² or more, the paper surface is sufficiently covered, so that high white paper gloss is easily obtained and the ink absorbability is sufficient. Further, if the coating amount exceeds 15 g / m ² , the print density may be lowered and the cost may be increased. Therefore, the amount is preferably 15 g / m ² or less.

  Next, although an example of the present invention is given and explained, the present invention is not limited to these examples. Further, “parts” and “%” indicate parts by mass and mass% unless otherwise specified. In addition, the number of parts shown in a mixing | blending is the quantity of a real component.

Example 1:
<Preparation of base paper>
1.0 part of cationized starch (Neotac 40T, manufactured by Nippon Food Processing Co., Ltd.), 0.2 part of acidic rosin sizing agent, 1 part of liquid sulfuric acid band and 100 parts of hardwood bleached kraft pulp (dissociation freeness of 520 ml) A paper stock containing an aluminosilicate composite salt (Thixolex 17: manufactured by Nissei Kyodo Co., Ltd.) having an average particle size of 10 μm and a specific surface area of 50 m ² / g, adjusted to an ash content of 5%, is blended. Paper making was performed with a paper machine to produce a base paper for the present invention having a basis weight of 180 g / m ² .
<Preparation of sizing solution>
Polyvinyl alcohol (PVA-117: manufactured by Kuraray Co., Ltd.) and olefin-based surface sizing agent (SS2552, manufactured by Seiko PMC) are mixed at a ratio of 1: 0.10, and prepared with water so that the solid content concentration is 4%. A sizing solution was obtained.
<Coating of size liquid>
The obtained size liquid was applied on both sides of the base paper with a size press so that the dry coating amount was 1 g / m ² per side, and dried with a cylinder dryer. Subsequently, a surface treatment was performed using a steel calender under conditions of a linear pressure of 40 kg / cm, 25 ° C., and two nips and one pass.
<Preparation of coating liquid for ink recording layer>
Water and 0.5 parts of acetic acid as a pH regulator were added to 100 parts of synthetic amorphous silica (Nipgel BY400: manufactured by Tosoh Silica), and a pigment slurry having a solid content concentration of 28% was prepared using a Cowles disperser. In this pigment slurry, 15 parts of polyvinyl alcohol (PVA-117: manufactured by Kuraray Co., Ltd.), 35 parts of polyethylene vinyl acetate binder (Polysol AD-13-50: manufactured by Showa Polymer Co., Ltd.), and 15 parts of ink fixing agent (SR1001: Taoka Chemical) Was added and stirred, and water was further added to obtain a coating solution for an ink recording layer having a solid content concentration of 20%.
<Formation of ink recording layer>
The obtained coating solution was coated on the communication surface with an air knife coater so that the dry coating amount was 8 g / m ^2, and dried with hot air using an air dryer. Further, a surface treatment was performed using a soft calender under conditions of a linear pressure of 30 kg / cm, 25 ° C., and two nips and one pass. Here, the Gurley air permeability after forming the ink recording layer was 80 seconds.
<Preparation of gloss layer coating solution>
Colloidal silica having an aggregate shape as a pigment (HS-M-20, primary particle size 25 nm, aggregate particle size 280 nm: manufactured by Nissan Chemical Co., Ltd.), polyvinyl alcohol (PVA117: manufactured by Kuraray Co., Ltd.), release agent A gloss layer coating solution having a solid content concentration of 20% was obtained using 1 part by mass of calcium stearate (Nopcoat C-104HS: manufactured by San Nopco).
<Glossy layer formation>
After coating the gloss layer coating solution with an air knife coater so that the dry coating amount is 8 g / m ^2, and then applying a 3% aqueous solution of borax and solidifying the coating layer surface, While in the wet state, the film was pressure-bonded to a cast drum having a surface temperature of 100 ° C. to prepare a postcard for inkjet recording of Example 1.

Example 2:
A postcard for inkjet recording was prepared according to Example 1 except that the pulp used for the base paper was hardwood bleached kraft pulp with a dissociation freeness of 680 ml.

Example 3:
A postcard for ink jet recording was prepared according to Example 1 except that the amount added was adjusted so that the aluminosilicate in the base paper had an ash content of 2%.

Example 4:
A postcard for inkjet recording was prepared according to Example 1 except that the amount added was adjusted so that the aluminosilicate in the base paper had an ash content of 9%.

Example 5:
Using calcined clay instead of aluminosilicate in the base paper, calcined clay (Ansilex 93: Engelhard, average particle size 2.8 μm, BET specific surface area 13.8 m ² / g) has an ash content of 5%. A postcard for inkjet recording was prepared in accordance with Example 1 except that the addition amount was adjusted and blended.

Example 6:
A postcard for inkjet recording was prepared according to Example 1, except that calcined clay was used in place of the aluminosilicate in the base paper, and the addition amount was adjusted so that the calcined clay had an ash content of 2%.

Example 7:
A postcard for inkjet recording was prepared according to Example 1 except that calcined clay was used in place of the aluminosilicate in the base paper and the addition amount was adjusted so that the calcined clay had an ash content of 9%.

Example 8:
An ink jet recording postcard was prepared in the same manner as in Example 1 except that the addition amount was adjusted so that the aluminosilicate contained in the base paper had an ash content of 3% and the calcined clay had an ash content of 3%.

Example 9:
An ink jet recording postcard was prepared in the same manner as in Example 1 except that the addition amount was adjusted so that the aluminosilicate contained in the base paper had an ash content of 1% and the calcined clay had an ash content of 1%.

Example 10:
An ink jet recording postcard was prepared in the same manner as in Example 1 except that the addition amount was adjusted so that the aluminosilicate contained in the base paper had an ash content of 4% and the calcined clay had an ash content of 4%.

Example 11:
An ink jet recording postcard was prepared according to Example 1, except that the size liquid was applied to both sides of the base paper with a size press so that the dry coating amount was 0.3 g / m ² per side.

Example 12:
An ink jet recording postcard was prepared according to Example 1 except that the size liquid was applied to both sides of the base paper with a size press so that the dry coating amount was 1.4 g / m ² per side.

Example 13:
An ink jet recording postcard was prepared according to Example 1, except that the mixing ratio of polyvinyl alcohol and olefinic surface sizing agent in the sizing solution was 1: 0.02.

Example 14
An ink jet recording postcard was prepared according to Example 1 except that the mixing ratio of polyvinyl alcohol and olefinic surface sizing agent in the sizing solution was 1: 0.15.

Reference Example 15:
An ink jet recording postcard was prepared according to Example 1, except that the surface sizing agent used in the sizing solution was changed from the olefin-based surface sizing agent to the styrene-based surface sizing agent (SS2562: manufactured by Seiko PMC).

Example 16:
An ink jet recording postcard was prepared according to Example 1, except that the surface sizing agent used in the sizing solution was changed from an olefin-based surface sizing agent to an ASA-based surface sizing agent (SS2590: manufactured by Seiko PMC).

Example 17:
The mixture ratio of polyvinyl alcohol and olefin surface sizing agent used in the sizing solution is 1: 0.10, and the mixing ratio of polyvinyl alcohol, styrene surface sizing agent and ASA is 1: 0.05: 0. A postcard for ink-jet recording was prepared in accordance with Example 1 except that it was changed to .05.

Example 18:
The polyvinyl alcohol and the olefin surface sizing agent in the sizing solution were changed to only polyacrylamide (ST5000: manufactured by Seiko PMC), and the dry coating amount on both sides of the base paper was 0.6 g / m ² per side. A postcard for inkjet recording was prepared according to Example 1 except that the coating was performed with a size press so that

Example 19:
Change the polyvinyl alcohol and olefin surface sizing agent in the sizing solution to polyacrylamide only, and apply it on the both sides of the base paper with a size press so that the dry coating amount is 2.4 g / m ² per side. A postcard for inkjet recording was prepared according to Example 1 except that it was processed.

Example 20:
An ink jet recording postcard was prepared according to Example 1, except that the dry coating amount of the ink recording layer was 4 g / m ² .

Example 21:
An ink jet recording postcard was prepared according to Example 1 except that the dry coating amount of the ink recording layer was 14 g / m ² .

Example 22:
An ink jet recording postcard was prepared according to Example 1, except that the size liquid was applied only to the opposite surface of the recording layer with a size press so that the dry coating amount was 0.3 g / m ² per side.

Example 23:
An ink jet recording postcard was prepared according to Example 1 except that the size liquid was applied only to the opposite surface of the recording layer with a size press so that the dry coating amount was 1.4 g / m ² per side.

Example 24:
The polyvinyl alcohol and olefin surface sizing agent in the sizing solution were changed to only polyacrylamide (ST5000: manufactured by Seiko PMC), and the dry coating amount was 0.6 g / side on only the opposite side of the recording layer. except that the coating in a size press so that m ² was prepared an ink jet recording postcard according to example 1.

Example 25:
Size press so that the polyvinyl alcohol and olefin surface sizing agent in the sizing liquid are changed to polyacrylamide only, and the dry coating amount is 2.4 g / m ² per side only on the opposite side of the recording layer. A postcard for ink-jet recording was prepared according to Example 1 except that the coating was carried out.

Example 26:
Implemented except that 100 parts of synthetic amorphous silica for ink recording layer (nip gel BY400: manufactured by Tosoh Silica Corporation) was 90 parts, and the remaining 10 parts were aluminum hydroxide (Hijilite H42M: Showa Denko). A postcard for ink jet recording was prepared according to Example 1.

Comparative Example 1:
A postcard for inkjet recording was prepared according to Example 1 except that the pulp used for the base paper was hardwood bleached kraft pulp with a dissociation freeness of 480 ml. However, there were many pits in the casting process, which hindered quality.

Comparative Example 2:
A postcard for ink-jet recording was prepared according to Example 1 except that it was a hardwood bleached kraft pulp with a dissociation freeness of 720 ml used for the base paper. However, picking and peeling frequently occurred in actual printing, and printing could not be performed.

Comparative Example 3:
An ink jet recording postcard was prepared according to Example 1, except that the amount added was adjusted so that the aluminosilicate in the base paper had an ash content of 0.5%. However, there were many pits in the casting process, which hindered quality.

Comparative Example 4:
An ink jet recording postcard was prepared according to Example 1, except that the amount added was adjusted so that the aluminosilicate in the base paper had an ash content of 11%. However, the coating layer dropped off during the casting process, and blanket stains occurred in actual printing, and printing could not be performed.

Comparative Example 5:
A postcard for inkjet recording was prepared according to Example 1, except that calcined clay was used instead of aluminosilicate in the base paper, and the addition amount was adjusted so that the calcined clay had an ash content of 0.5%. . However, there were many pits in the casting process, which hindered quality.

Comparative Example 6:
A postcard for inkjet recording was prepared according to Example 1 except that calcined clay was used instead of aluminosilicate in the base paper, and the addition amount was adjusted so that the calcined clay had an ash content of 11%. However, the coating layer dropped off during the casting process, and blanket stains occurred in actual printing, and printing could not be performed.

Comparative Example 7:
An ink jet recording postcard was prepared in the same manner as in Example 1 except that the addition amount was adjusted so that the aluminosilicate in the base paper had an ash content of 6% and the calcined clay had an ash content of 6%. However, the coating layer dropped off during the casting process, and blanket stains occurred in actual printing, and printing could not be performed.

Comparative Example 8:
A postcard for inkjet recording was prepared according to Example 1 except that the aluminosilicate and the calcined clay in the base paper were not used. However, there were many pits in the casting process, which hindered quality.

Comparative Example 9:
An ink jet recording postcard was prepared according to Example 1, except that the size liquid was applied to both sides of the base paper with a size press so that the dry coating amount was 0.1 g / m ² per side. However, picking and peeling frequently occurred in actual printing, and printing could not be performed.

Comparative Example 10:
An ink jet recording postcard was prepared according to Example 1 except that the size liquid was applied to both sides of the base paper with a size press so that the dry coating amount was 1.7 g / m ² per side. However, the cost of chemicals was high, and actual use was not possible.

Comparative Example 11:
An ink jet recording postcard was prepared according to Example 1 except that the mixing ratio of polyvinyl alcohol and olefinic surface sizing agent in the sizing solution was 1: 0.007. However, the air permeability after coating the ink recording layer was as high as 123 seconds, and many pits occurred during the casting process.

Comparative Example 12:
An ink jet recording postcard was prepared according to Example 1 except that the mixing ratio of polyvinyl alcohol and olefinic surface sizing agent in the sizing solution was 1: 0.25. However, the cost of chemicals was high, and actual use was not possible.

Comparative Example 13:
An ink jet recording postcard was prepared according to Example 1, except that the surface sizing agent used in the sizing solution was changed from an olefin-based surface sizing agent to an alkyl ketene dimer (SE2360: manufactured by Seiko PMC). However, the air permeability after coating the ink recording layer was as high as 107 seconds, and pits were frequently generated during the casting process.

Comparative Example 14:
Polyvinyl alcohol and olefinic surface sizing agent in the sizing liquid were changed to oxidized starch (Oji Ace A: manufactured by Oji Cornstarch Co., Ltd.), and the dry coating amount on both sides of the base paper was 1.5 g / side. except that the coating in a size press so that m ² was prepared an ink jet recording postcard according to example 1. However, paper peeling occurred during actual printing, and printing was not possible.

Comparative Example 15:
An ink jet recording postcard was prepared according to Example 1 except that the dry coating amount of the ink recording layer was 2 g / m ² . However, ink jet printability was poor and bleeding occurred.

Comparative Example 16
An ink jet recording postcard was prepared according to Example 1 except that the dry coating amount of the ink recording layer was 17 g / m ² . However, the coating layer dropped during operation, and the blanket was soiled during actual printing. In addition, the cost of chemicals was high, and actual use was not possible.

Comparative Example 17:
The polyvinyl alcohol and the olefinic surface sizing agent in the sizing solution were changed to only polyacrylamide (ST5000: manufactured by Seiko PMC), and the dry coating amount on both sides of the base paper was 0.4 g / m ² per side. A postcard for inkjet recording was prepared according to Example 1 except that the coating was performed with a size press so that However, paper peeling occurred during actual printing, and printing was not possible.

Comparative Example 18:
The polyvinyl alcohol and the olefin surface sizing agent in the sizing solution were changed to only polyacrylamide (ST5000: manufactured by Seiko PMC), and the dry coating amount on both sides of the base paper was 2.6 g / m ² per side. A postcard for inkjet recording was prepared according to Example 1 except that the coating was performed with a size press so that However, the cost of chemicals was high, and actual use was not possible.

  Table 1 shows the evaluation results of the air permeability, ink jet printing suitability, cast suitability, and printing strength after the ink recording layer coating for the ink jet recording paper obtained in the above Examples and Comparative Examples.

<Evaluation method>
The obtained postcard for inkjet recording was evaluated according to the following methods in the same environment after humidity control for 24 hours in a constant temperature and humidity chamber of 23 ° C.-50% RH.

<Inkjet printing aptitude evaluation>
A photographic image is printed using a commercially available full-color ink jet printer (trade name: PM-900C, manufactured by Seiko Epson Corporation), and the ink is visually observed in addition to unevenness in image details, blurring at the boundary portion, vividness of color development, and the like. The printability was evaluated.

The inkjet printability evaluation was described according to the following procedure.
A: Excellent B: Good (practical level)
Δ: Slightly inferior (practical lower limit level)
X: Inferior (not suitable for practical use)

<Print strength evaluation>
A postal code frame, a stamp pasting frame, or a test pattern was printed on the address side with an actual printing machine, and evaluation was performed based on the presence or absence of picks such as white spots and peeling, and the degree of dirt on the blanket. The printing strength evaluation was described according to the following procedure.
◎: Practical level or higher ○: Practical level △: Some printing has trouble (not practical level)
X: Printing is not possible (not practical level).

<Economic evaluation>
Evaluation was made by comprehensively considering productivity such as chemical material costs, pit generation, and coating layer removal. The economic evaluation was described in the following manner.
◎: Profit level or higher ○: Profit level (practical level)
Δ: Unprofitable (not practical level)
×: Unprofitable, unsuitable (not practical level)

<Cast operability evaluation>
The gloss layer of the postcard for inkjet recording was observed, and the presence or absence of pits and the presence or absence of the coating layer was evaluated according to the following procedure.
◎: No pit generation, no coating layer falling off, practical level ○: Some pits are seen and / or some coating layer fall off, but practical level △: Pits are generated and / or coating layer Is not practical level. ×: There are many pits and / or coating layer is dropped (entire surface), not practical level.

Claims (4)

A paper support, at least one ink recording layer formed on the paper support and containing a pigment mainly composed of synthetic amorphous silica and an adhesive resin, and formed on the ink recording layer and luster layer, have a, the gloss layer is an ink jet recording postcard formed by a cast coating method,
(1) The paper support has wood pulp as a main component, its freeness (CSF) is 500 ml or more and 700 ml or less, and either an aluminosilicate or a calcined clay is used alone in the paper support or an aluminosilicate. Containing 1 to 10% by mass of the mixture of baked clay and the weight of the whole paper support,
(2) Polyacrylamide is coated only on both sides of the paper support or on the opposite side of the recording layer in a range of dry coating amount of 0.5 to 2.5 g / m ² per side ;
(3) The ink recording layer has a dry coating amount of 3 to 15 g / m ² ,
A postcard for inkjet recording, characterized by A paper support, at least one ink recording layer formed on the paper support and containing a pigment mainly composed of synthetic amorphous silica and an adhesive resin, and formed on the ink recording layer and luster layer, have a, the gloss layer is an ink jet recording postcard formed by a cast coating method,
(1) The paper support has wood pulp as a main component, its freeness (CSF) is 500 ml or more and 700 ml or less, and either an aluminosilicate or a calcined clay is used alone in the paper support or an aluminosilicate. Containing 1 to 10% by mass of the mixture of baked clay and the weight of the whole paper support,
(2) only the opposite surface of both sides or the recording layer of the paper support, the size solution using a combination of polyvinyl alcohol and a surface sizing agent per surface drying coating amount 0.2 to 1.5 g / m ² Coated in range
(3) The ink recording layer has a dry coating amount of 3 to 15 g / m ² .
(4) The surface sizing agent is an olefin sizing agent or an alkenyl succinic anhydride used alone or a mixture thereof.
An ink jet recording postcard characterized by the above. JIS after providing the ink recording layer
P 8117: The postcard for inkjet recording according to claim 1 or 2 , wherein the air permeability resistance (Gurley) measured according to 1998 is 50 seconds or more and 100 seconds or less. Mixing ratio of polyvinyl alcohol with polyvinyl alcohol and a surface sizing agent to be applied to the surface of the paper support: surface sizes = 1: to claim 2, wherein is (0.01 to 0.20) The postcard for inkjet recording as described.