JP2017127973A - Inkjet recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet recording material having good coating layer strength and moist heat coating layer strength while having excellent ink absorbency and color developability being qualities of inkjet recording.SOLUTION: There is provided an inkjet recording material having an absorptive support and an undercoat layer and a top coat layer on the absorptive support, where the undercoat layer contains at least one selected from an urethane resin having a carboxyl group and a styrene-butadiene resin having a carboxyl group, a boric acid compound or a borate compound, silica, and a resin having a carbodiimide group, and the top coat layer contains inorganic fine particles and polyvinyl alcohols.SELECTED DRAWING: None

Description

  The present invention relates to an ink jet recording material having a coating layer.

  As an ink jet recording material having high ink absorbability and excellent crack resistance, an ink jet recording material having an ink receiving layer on a support, wherein the ink receiving layer is present in the presence of an organic compound having a crosslinkable group and a cationic polymer. A compound containing a dispersed silica dispersion and a hydrophilic polymer having a hydroxyl group, wherein the organic compound having a crosslinkable group has two or more groups selected from the group consisting of a carbodiimide group and an oxazoline group Inkjet recording materials are known (see, for example, Patent Document 1).

  As a sheet for inkjet recording excellent in improvement of scratch resistance in a wet state, a base material and an ink receiving layer are provided, and the ink receiving layer includes (a) dimethylamine and epichlorohydrin as additives. An inkjet recording sheet containing a cationic resin composed of at least one selected from a polymer and polyallylamine and a compound having (b) a carbodiimide group is known (for example, see Patent Document 2).

Japanese Patent Laid-Open No. 2005-074874 JP 2004-345110 A

  In recent years, the global environment has been warmed, and there are cases where the recording medium is exposed to a high temperature and humidity environment exceeding 45% 70% RH during storage or transportation of the ink jet recording medium. Therefore, an inkjet recording material having a coating layer is required to have a quality that does not decrease the physical strength of the coating layer after being placed in a high-temperature and high-humidity environment, that is, a wet heat coating layer strength.

  The recording material of Patent Document 1 is excellent in crack resistance of the coating layer, but the wet heat coating layer strength has not been studied and is insufficient. The recording sheet of Patent Document 2 is excellent in scratch resistance in a wet state, but the wet heat coating layer strength has not been studied and is insufficient.

  An object of the present invention is to provide an ink jet recording material having excellent coating layer strength and wet heat coating layer strength while being excellent in ink absorbability and color developability, which are the quality of ink jet recording.

  The object of the present invention is to provide an absorbent support and an inkjet recording material having an undercoat layer and an overcoat layer on the absorbent support, wherein the undercoat layer is a urethane resin having a carboxyl group and a styrene having a carboxyl group. -Inkjet recording containing at least one selected from butadiene-based resins, boric acid compounds or borate compounds, silica, and resins having a carbodiimide group, wherein the overcoat layer contains inorganic fine particles and polyvinyl alcohols. Achieved by the material.

  Preferably, at least one of the inorganic fine particles is alumina hydrate, and the content of the alumina hydrate in the overcoat layer is more than 70% by mass with respect to the inorganic fine particles in the overcoat layer.

  According to the present invention, it is possible to provide an ink jet recording material having excellent coating layer strength and wet heat coating layer strength while being excellent in ink absorbability and color developability, which are the quality of ink jet recording.

Hereinafter, the present invention will be described in detail.
In the present invention, the undercoat layer is a coating layer positioned on the absorbent support side with respect to the overcoat layer, and the overcoat layer is a coating layer positioned on the upper side of the undercoat layer with respect to the absorbent support. . In this specification, “on the undercoat layer” refers to the absorbent support so that it refers to “on” the undercoat layer based on the absorbent support.

  In the ink jet recording material of the present invention, the undercoat layer has at least one selected from a urethane-based resin having a carboxyl group and a styrene-butadiene-based resin having a carboxyl group, a boric acid compound or a borate compound, silica, And a resin having a carbodiimide group.

  When the undercoat layer contains a resin having a carbodiimide group and at least one selected from a urethane-based resin having a carboxyl group and a styrene-butadiene-based resin having a carboxyl group, the carbodiimide group reacts with the carboxyl group. Excellent wet heat coating layer strength can be obtained.

The resin containing a carbodiimide group is a resin having a carbodiimide group (—N═C═N—) in the molecule. A resin having a carbodiimide group is a water-soluble or water-dispersible carbodiimide obtained by sealing a terminal isocyanate group of a condensation reaction product obtained by decarbonization condensation of diisocyanates or diisocyanates and triisocyanates with a hydrophilic group. A compound.
As the diisocyanates and triisocyanates, alicyclic isocyanates, aliphatic isocyanates and aromatic isocyanates, particularly those having at least two, particularly two isocyanate groups in the molecule are preferable. Examples of the diisocyanates and triisocyanates include 4,4'-dicyclohexylmethane diisocyanate (HMDI), tetramethylxylylene diisocyanate (TMXDI), for isocyanate compounds that do not have an isocyanate group bonded to a carbon atom of a methylene group in the molecule. Isophorone diisocyanate (IPDI), 2,4,6-triisopropylphenyl diisocyanate (TIDI), 4,4'-diphenylmethane diisocyanate (MDI), tolylene diisocyanate (TDI), hydrogenated tolylene diisocyanate (HTDI), etc. Hexamethylene diisocyanate (HDI) or hydrogenated xylene for alicyclic, aliphatic and aromatic isocyanates having two or more isocyanate groups bonded to carbon atoms of the methylene group Range isocyanate (H6XDI), xylylene diisocyanate (XDI), 2,2,4-trimethylhexamethylene diisocyanate (TMHDI), 1,12-diisocyanate dodecane (DDI), norbornane diisocyanate (NBDI), and 2,4-bis- And (8-isocyanate octyl) -1,3-dioctylcyclobutane (OCDI).
The compound that seals the terminal isocyanate group is a water-soluble or water-dispersible organic compound having a group capable of reacting with an isocyanate group, for example, a bifunctional water-dispersible organic compound such as polyethylene glycol or polypropylene glycol And monofunctional organic compounds having a cationic functional group (for example, a group containing nitrogen) or an anionic functional group (for example, a group containing a sulfonyl group). . In particular, polyethylene glycol monomethyl ether, polypropylene glycol monomethyl ether, and the like are preferable.

  The carbodiimide equivalent of the resin having a carbodiimide group is preferably 600 or less, more preferably 500 or less, and still more preferably 400 or less. The lower limit is preferably 300 or more, and more preferably 350 or more. The carbodiimide equivalent referred to here is the chemical formula amount per mole of carbodiimide group.

  The content of the resin having a carbodiimide group in the undercoat layer is preferably 0.5% by mass or more and 10% by mass or less based on the dry solid content of the undercoat layer.

  Resins having a carbodiimide group are commercially available, for example, from Nisshinbo Chemical Co., Ltd.

  The urethane resin is a resin mainly composed of urethane bonds, and is a conventionally known polyhydric alcohol compound or polyhydric amine having a compound having two or more isocyanate groups and two or more active hydrogen groups. It is a polymer having a urethane bond obtained by reacting a similar compound.

  The urethane-based resin having a carboxyl group includes two compounds having a carboxyl group, a compound having two or more isocyanate groups, a polyhydric alcohol compound or polyamine compound having two or more active hydrogen groups, and a carboxyl group. It can be obtained by reacting a polyhydric alcohol compound having the above active hydrogen group.

  Examples of polyhydric alcohol compounds having a carboxyl group and two or more active hydrogen groups include 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, and 2,2-dimethylolvaleric acid. Etc.

  The amount of the polyhydric alcohol compound having two or more active hydrogen groups while having a carboxyl group is selected from polyhydric alcohol compounds and polyamines having two or more active hydrogen groups, and a carboxyl group. It is preferably 0.1 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass in total of the polyhydric alcohol compounds having two or more active hydrogen groups while having them.

  The urethane-based resin having a carboxyl group is commercially available from, for example, DIC and Sanyo Chemical Industries.

  The styrene-butadiene resin is a resin mainly composed of a copolymer of a styrene monomer compound and butadiene. The styrene monomer compound is a styrene derivative having a substituent on a vinyl group such as styrene or α-methylstyrene, and a derivative having a substituent on a benzene ring such as vinyltoluene or p-chlorostyrene.

  The styrene-butadiene resin having a carboxyl group can be obtained by copolymerizing a styrene monomer compound, butadiene, and a monomer compound having a carboxyl group such as acrylic acid or methacrylic acid. As for the monomer compound which has a carboxyl group, 30 mol% or less is preferable with respect to all the monomers in resin.

  Styrene-butadiene resins having a carboxyl group are commercially available from, for example, JSR and Nippon A & L.

  The content in at least one undercoat layer selected from a urethane resin having a carboxyl group and a styrene-butadiene resin having a carboxyl group is 3 parts by mass with respect to 1 part by mass of the resin having a carbodiimide group in the undercoat layer. The amount is preferably 35 parts by mass or less. Moreover, 30 to 100 mass parts is preferable with respect to 100 mass parts of inorganic pigments containing silica in the undercoat layer.

  The undercoat layer can contain a conventionally known binder in addition to at least one selected from a urethane-based resin having a carboxyl group and a styrene-butadiene-based resin having a carboxyl group, as long as the effects of the present invention are not impaired. Examples of conventionally known binders include starch derivatives such as oxidized starch, etherified starch and phosphate esterified starch, cellulose derivatives such as carboxymethyl cellulose and hydroxyethyl cellulose, casein, gelatin, soy protein, pullulan, gum arabic, karaya gum, Natural polymer resins such as albumin or derivatives thereof, polyvinyl alcohols containing various modifications such as various saponification and polymerization degrees and silanol modification, polyvinylpyrrolidone, polyacrylamide, polyethyleneimine, polypropylene glycol, polyethylene glycol, maleic anhydride Resins, ethylene-vinyl acetate resins, or functional group-modified resins with functional group-containing monomers such as carboxy groups of these various resins, thermosetting synthetic resins such as melamine resins and urea resins, acrylic resins It can be mentioned polyester resin, polyvinyl butyral and the like.

  When the undercoat layer contains a boric acid compound or a borate compound, the boric acid compound or borate compound and polyvinyl alcohol in the overcoat layer to be described later are used in the topcoat layer coating solution in the step of producing an inkjet recording material. When the coating is applied onto the undercoat layer, it can interact to obtain crack suppression, transparency and coating layer strength of the overcoat layer. Suppression of cracking and transparency affect color development.

  The boric acid compound is a general term for oxygen acids generated by dihydration of diboron trioxide. Examples of boric acid compounds include orthoboric acid, metaboric acid, hypoboric acid, tetraboric acid, pentaboric acid and the like.

A borate compound is a salt of an oxygen acid having boron as a central atom, and is a general term for compounds represented by the following representative formulas.
xM ¹ ₂ O · yB ₂ O ₃ · zH ₂ O
Here, M ¹ is a case of a monovalent metal ion, and z includes 0.
When y / x corresponds to 1/3, 1/2, 1, 2, 5/2, 4, orthoborate, diborate, metaborate, tetraborate, pentaborate This is called octaborate.
Examples of borate compounds include cobalt borate, zinc borate (zinc tetraborate, zinc metaborate, etc.), aluminum borate / potassium borate, ammonium borate (ammonium metaborate, ammonium tetraborate, pentaborate) Ammonium, ammonium octaborate, etc.), cadmium borate (cadmium orthoborate, cadmium tetraborate, etc.), potassium borate (potassium metaborate, potassium tetraborate, potassium pentaborate, potassium hexaborate, octaborate) Potassium), silver borate (silver metaborate, silver tetraborate, etc.), copper borate (cupric borate, copper metaborate, copper tetraborate, etc.), sodium borate (sodium metaborate, diborate) Sodium phosphate, sodium tetraborate, sodium pentaborate, sodium hexaborate, sodium octaborate, etc.), lead borate (metaphor Lead oxide, lead hexaborate, etc.), nickel borate (nickel orthoborate, nickel diborate, nickel tetraborate, nickel octaborate, etc.), barium borate (barium orthoborate, barium metaborate, diborate) Barium, barium tetraborate, etc.), bismuth borate, magnesium borate (magnesium orthoborate, magnesium diborate, magnesium metaborate, trimagnesium tetraborate, pentamagnesium tetraborate, etc.), manganese borate (boric acid) And manganese borate (manganese metaborate, manganese tetraborate, etc.), lithium borate (lithium metaborate, lithium tetraborate, lithium pentaborate, etc.). In addition to these, examples of borate compounds include borate minerals such as borax, carnite, inyoite, olivine, suian stone, and zyberite.

Among these boric acid compounds and borate compounds, the boric acid compound is preferably orthoboric acid, and the borate compound is preferably borax. Moreover, a boric acid compound and a borate compound can be used in combination of 2 or more types.
The content of the boric acid compound or borate compound in the undercoat layer is preferably 0.1 g / m ² or more and 3 g / m ² or less in terms of solid content in terms of orthoboric acid (H ₃ BO ₃ ).

  The silica is a conventionally known wet synthetic silica obtained by a known method such as gas phase method silica, precipitation method silica, gel method silica, and sol method silica typified by colloidal silica.

  The undercoat layer can contain a conventionally known inorganic pigment in addition to silica as long as the effects of the present invention are not impaired. Examples of conventionally known inorganic pigments include light calcium carbonate, heavy calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, diatomaceous earth, satin white, aluminum silicate, Calcium silicate, magnesium silicate, tin oxide sol, niobium oxide sol, cerium oxide sol, lanthanum oxide sol, yttrium oxide sol, colloidal alumina, aluminum hydroxide, alumina, alumina hydrate, lithopone, zeolite, hydrous halloysite, magnesium carbonate, magnesium hydroxide Etc.

  By selecting silica among various inorganic pigments, it is possible to achieve both ink absorbency and wet heat coating layer strength. The reason for this is unclear, but since silica is a relatively large specific surface area among inorganic pigments and carbodiimide groups are relatively easy to adsorb resins having a carbodiimide group, urethane resins and styrene-butadiene resins. It is considered that the reaction frequency with the carboxyl group is improved, and as a result, ink absorbency and wet heat coating layer strength can be obtained.

  The ink jet recording material of the present invention contains inorganic fine particles and polyvinyl alcohol in the overcoat layer.

When the topcoat layer contains polyvinyl alcohols, the transparency and coating strength of the topcoat layer can be obtained in combination with the boric acid compound or borate compound of the undercoat layer.
Polyvinyl alcohols are various polyvinyl alcohols having various saponification degrees and polymerization degrees, and various modified polyvinyl alcohols such as silanol modification and acetoacetyl modification. “Containing polyvinyl alcohol” means containing at least one selected from various polyvinyl alcohols and various modified polyvinyl alcohols.

  In the present invention, the content of the polyvinyl alcohol in the overcoat layer is preferably 5% by mass or more and 30% by mass or less with respect to the inorganic fine particles in the overcoat layer.

  The topcoat layer can contain a conventionally known binder in addition to the polyvinyl alcohols as long as the effects of the present invention are not impaired. Examples of conventionally known binders include starch derivatives such as oxidized starch, etherified starch and phosphate esterified starch, cellulose derivatives such as carboxymethyl cellulose and hydroxyethyl cellulose, casein, gelatin, soy protein, pullulan, gum arabic, karaya gum, Natural polymer resins such as albumin or derivatives thereof, polyvinylpyrrolidone, polyacrylamide, polyethyleneimine, polypropylene glycol, polyethylene glycol, maleic anhydride resin, styrene-butadiene resin, acrylic resin, methyl methacrylate-butadiene resin, Ethylene-vinyl acetate resins, or functional group-modified resins with functional group-containing monomers such as carboxy groups of these resins, thermosetting synthetic resins such as melamine resins and urea resins, urethane resins, polymers Ester resin, polyvinyl butyral, and the like.

  The inorganic fine particles are inorganic particles having an average particle diameter of 100 μm or less. The average particle diameter is determined from the image obtained by photographing the overcoat layer of the ink jet recording material with an electron microscope, and the observed particle is regarded as a sphere having an equal area, and the sphere diameter is defined as the average particle diameter of the particle. It is an average particle diameter obtained by measuring 100 particles to be observed.

  Inorganic fine particles are conventionally known, for example, silica, light calcium carbonate, heavy calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, diatomaceous earth, satin. Examples thereof include white, aluminum silicate, calcium silicate, magnesium silicate, colloidal alumina, aluminum hydroxide, alumina, alumina hydrate, lithopone, zeolite, hydrous halloysite, magnesium carbonate, magnesium hydroxide and the like.

  The inorganic fine particles are preferably alumina hydrate in an amount of more than 70% by mass with respect to the inorganic fine particles in the overcoat layer. When the fine inorganic particles in the topcoat layer are hydrated alumina, the transparency is further improved and a better color developability can be obtained.

In the present invention, alumina hydrate can be represented by the general formula Al ₂ O ₃ .nH ₂ O. Alumina hydrates are classified into dipsite, vialite, norstrandite, boehmite, boehmite gel (pseudoboehmite), diaspore, amorphous amorphous, etc., depending on the composition and crystal form. In particular, in the above formula, when the value of n is 1, it represents an alumina hydrate having a boehmite structure, and when n is more than 1 and less than 3, it represents an alumina hydrate having a pseudo boehmite structure, where n is 3 or more represents an amorphous alumina hydrate. In particular, the preferred alumina hydrate for the present invention is an alumina hydrate having a pseudo boehmite structure in which at least n is more than 1 and less than 3.

  The undercoat layer and the overcoat layer can contain various conventionally known additives as necessary. Examples of conventionally known additives include dye fixing agents, pigment dispersants, thickeners, rheology control agents, viscosity stabilizers, pH adjusters, surfactants, antifoaming agents, antifoaming agents, mold release agents, Foaming agent, penetrating agent, coloring dye, coloring pigment, fluorescent whitening agent, ultraviolet absorber, antioxidant, leveling agent, antiseptic, antibacterial agent, water resistance agent, wet paper strength enhancer, dry paper strength enhancer Etc.

  The absorbent support is paper obtained by a conventionally known papermaking method. Examples of the absorbent support include chemical pulps such as LBKP and NBKP, mechanical pulps such as GP, PGW, RMP, TMP, CTMP, CMP, and CGP, wood pulp such as waste paper pulp such as DIP, and conventionally known fillers. As a main component, a paper material containing various additives such as a binder, a sizing agent, a fixing agent, a yield improver, a cationizing agent and a paper strength enhancer, as required, is used as a long net paper machine, a circular net paper machine. Examples thereof include base paper manufactured by various apparatuses such as a twin wire paper machine, and further, high-quality paper obtained by subjecting the base paper to calendar treatment, surface sizing treatment or surface treatment with a starch derivative, polyvinyl alcohol, or the like. Furthermore, coated paper in which a coated layer is provided on base paper or high-quality paper is included as an absorbent support. Further, as the absorbent support, a high-quality paper subjected to a surface size treatment or a surface treatment and then a calendar treatment and a coated paper subjected to a calendar treatment after providing a coating layer are also included.

  In the present invention, a coating layer can be provided between the absorbent support and the undercoat layer, between the undercoat layer and the overcoat layer, or on the overcoat layer as long as the effects of the present invention are not impaired.

  The undercoat layer and the overcoat layer can be obtained by coating and drying each coating solution by a conventionally known coating method and drying method. Examples of coating methods include air knife coaters, curtain coaters, slide lip coaters, die coaters, blade coaters, bill blade coaters, short dwell blade coaters, gate roll coaters, bar coaters, rod coaters, roll coaters, size presses, etc. Examples of the method include using various coating apparatuses. As a drying method, for example, a method using various drying devices such as a straight tunnel dryer, an arch dryer, an air loop dryer, a hot air dryer such as a sine curve air float dryer, an infrared heating dryer, and a dryer using a microwave. Can be mentioned.

  The ink jet recording material can be calendered for the purpose of adjusting the glossiness, smoothness, and thickness of the white paper. Examples of the calendar processing device include a machine calendar, a gloss calendar, a super calendar, and a soft calendar. Moreover, a glossy surface can be formed using a conventionally known casting method.

  Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples. In Examples, “parts by mass” and “% by mass” indicate values of dry solids or substantial components unless otherwise specified. A coating amount shows the value of dry solid content.

<Absorptive support>
80 parts by mass of hardwood bleached kraft pulp (LBKP, freeness 370 mlcsf) and 20 parts by weight of softwood bleached kraft pulp (NBKP, freeness 400 mlcsf), 13 parts by weight of talc, 3 parts by weight of sulfuric acid band, commercially available rosin sizing agent 0.2 A base paper having a basis weight of 100 g / m ² is made from a slurry having a concentration of 1% by mass obtained by mixing water and 0.3 parts by weight of cationic starch in water using a long net paper machine. An absorptive support was produced by attaching starch to a solid content of 2 g / m ² per side.

<Preparation of undercoat layer coating solution 1>
A dispersed water solution in which 7 parts by mass of borax and 7 parts by mass of orthoboric acid were dissolved in water was obtained. Disperse 20 parts by mass of colloidal silica (Snowtex 30, manufactured by Nissan Chemical Industries, Ltd.) and 100 parts by mass of wet synthetic silica (Mizukasil P-78A, manufactured by Mizusawa Chemical Co., Ltd.) in the dispersion solution. Obtained. Next, 60 parts by mass of a urethane-based resin having a carboxyl group as a binder (Hydran WLS202, manufactured by DIC), 2 parts by mass of a rheology control agent (BYK E-420, manufactured by Big Chemie Japan), a carbodiimide group 5 parts by mass of a resin (Carbodilite V-02, manufactured by Nisshinbo Chemical Co., Ltd.) having a coating composition was added and mixed, and the coating solution concentration was adjusted to 15% by mass to obtain an undercoat layer coating solution 1.

<Preparation of undercoat layer coating solution 2>
A dispersed water solution in which 7 parts by mass of borax and 7 parts by mass of orthoboric acid were dissolved in water was obtained. Disperse 20 parts by mass of colloidal silica (Snowtex 30, manufactured by Nissan Chemical Industries, Ltd.) and 100 parts by mass of wet synthetic silica (Mizukasil P-78A, manufactured by Mizusawa Chemical Co., Ltd.) in the dispersion solution. Obtained. Next, 60 parts by mass of a urethane-based resin having a carboxyl group as a binder (Hydran WLS202, manufactured by DIC), 2 parts by mass of a rheology control agent (BYK E-420, manufactured by Big Chemie Japan), a carbodiimide group 5 parts by weight of a resin (Carbodilite V-02-L2, manufactured by Nisshinbo Chemical Co., Ltd.) was added and mixed, and the coating solution concentration was adjusted so as to be 15% by mass, whereby an undercoat layer coating solution 2 was obtained.

<Preparation of undercoat layer coating solution 3>
A dispersed water solution in which 7 parts by mass of borax and 7 parts by mass of orthoboric acid were dissolved in water was obtained. Disperse 20 parts by mass of colloidal silica (Snowtex 30, manufactured by Nissan Chemical Industries, Ltd.) and 100 parts by mass of wet synthetic silica (Mizukasil P-78A, manufactured by Mizusawa Chemical Co., Ltd.) in the dispersion solution. Obtained. Next, 60 parts by mass of a urethane-based resin having a carboxyl group as a binder (Hydran WLS202, manufactured by DIC), 2 parts by mass of a rheology control agent (BYK E-420, manufactured by Big Chemie Japan), a carbodiimide group 5 parts by mass of a resin (Carbodilite SV-02, manufactured by Nisshinbo Chemical Co., Ltd.) having a viscosity of 15% by mass was added and mixed to adjust the coating solution concentration to 15% by mass to obtain an undercoat layer coating solution 3.

<Preparation of undercoat layer coating solution 4>
A dispersed water solution in which 7 parts by mass of borax and 7 parts by mass of orthoboric acid were dissolved in water was obtained. Disperse 20 parts by mass of colloidal silica (Snowtex 30, manufactured by Nissan Chemical Industries, Ltd.) and 100 parts by mass of wet synthetic silica (Mizukasil P-78A, manufactured by Mizusawa Chemical Co., Ltd.) in the dispersion solution. Obtained. Next, 60 parts by mass of a urethane-based resin having a carboxyl group as a binder (Hydran WLS202, manufactured by DIC), 2 parts by mass of a rheology control agent (BYK E-420, manufactured by Big Chemie Japan), a carbodiimide group 5 parts by mass of a resin (Carbodilite V-04, manufactured by Nisshinbo Chemical Co., Ltd.) having a pH of 5 was added and mixed, and the coating solution concentration was adjusted to 15% by mass to obtain an undercoat layer coating solution 4.

<Preparation of undercoat layer coating solution 5>
A dispersed water solution in which 7 parts by mass of borax and 7 parts by mass of orthoboric acid were dissolved in water was obtained. Disperse 20 parts by mass of colloidal silica (Snowtex 30, manufactured by Nissan Chemical Industries, Ltd.) and 100 parts by mass of wet synthetic silica (Mizukasil P-78A, manufactured by Mizusawa Chemical Co., Ltd.) in the dispersion solution. Obtained. Next, 60 parts by mass of a urethane-based resin having a carboxyl group as a binder (Hydran WLS202, manufactured by DIC), 2 parts by mass of a rheology control agent (BYK E-420, manufactured by Big Chemie Japan), a carbodiimide group 5 parts by weight of a resin (Carbodilite V-10, manufactured by Nisshinbo Chemical Co., Ltd.) having a pH of 5 was added and mixed, and the coating solution concentration was adjusted so as to be 15% by mass, whereby an undercoat layer coating solution 5 was obtained.

<Preparation of undercoat layer coating solution 6>
A dispersed water solution in which 7 parts by mass of borax and 7 parts by mass of orthoboric acid were dissolved in water was obtained. Disperse 20 parts by mass of colloidal silica (Snowtex 30, manufactured by Nissan Chemical Industries, Ltd.) and 100 parts by mass of wet synthetic silica (Mizukasil P-78A, manufactured by Mizusawa Chemical Co., Ltd.) in the dispersion solution. Obtained. Next, 60 parts by mass of a urethane-based resin having a carboxyl group as a binder (Hydran WLS202, manufactured by DIC), 2 parts by mass of a rheology control agent (BYK E-420, manufactured by Big Chemie Japan), a carbodiimide group 5 parts by mass of a resin (Carbodilite SW-12G, manufactured by Nisshinbo Chemical Co., Ltd.) having a pH of 5 was added and mixed, and the coating solution concentration was adjusted to 15% by mass to obtain an undercoat layer coating solution 6.

<Preparation of undercoat layer coating solution 7>
A dispersed water solution in which 7 parts by mass of borax and 7 parts by mass of orthoboric acid were dissolved in water was obtained. Disperse 20 parts by mass of colloidal silica (Snowtex 30, manufactured by Nissan Chemical Industries, Ltd.) and 100 parts by mass of wet synthetic silica (Mizukasil P-78A, manufactured by Mizusawa Chemical Co., Ltd.) in the dispersion solution. Obtained. Next, 60 parts by mass of a urethane-based resin having a carboxyl group as a binder (Hydran WLS202, manufactured by DIC), 2 parts by mass of a rheology control agent (BYK E-420, manufactured by Big Chemie Japan), a carbodiimide group 5 parts by mass of a resin (Carbodilite E-02, manufactured by Nisshinbo Chemical Co., Ltd.) having a pH of 5 was added and mixed, and the coating solution concentration was adjusted to 15% by mass to obtain an undercoat layer coating solution 7.

<Preparation of undercoat layer coating solution 8>
A dispersed water solution in which 7 parts by mass of borax and 7 parts by mass of orthoboric acid were dissolved in water was obtained. Disperse 20 parts by mass of colloidal silica (Snowtex 30, manufactured by Nissan Chemical Industries, Ltd.) and 100 parts by mass of wet synthetic silica (Mizukasil P-78A, manufactured by Mizusawa Chemical Co., Ltd.) in the dispersion solution. Obtained. Next, 60 parts by mass of a urethane-based resin having a carboxyl group as a binder (Hydran WLS202, manufactured by DIC), 2 parts by mass of a rheology control agent (BYK E-420, manufactured by Big Chemie Japan), a carbodiimide group 5 parts by weight of a resin (Carbodilite E-03A, manufactured by Nisshinbo Chemical Co., Ltd.) was added and mixed, and the concentration of the coating solution was adjusted to 15% by weight, whereby an undercoat layer coating solution 8 was obtained.

<Preparation of undercoat layer coating solution 9>
A dispersed water solution in which 7 parts by mass of borax and 7 parts by mass of orthoboric acid were dissolved in water was obtained. Disperse 20 parts by mass of colloidal silica (Snowtex 30, manufactured by Nissan Chemical Industries, Ltd.) and 100 parts by mass of wet synthetic silica (Mizukasil P-78A, manufactured by Mizusawa Chemical Co., Ltd.) in the dispersion solution. Obtained. Next, 60 parts by mass of a urethane-based resin having a carboxyl group as a binder (Hydran WLS202, manufactured by DIC), 2 parts by mass of a rheology control agent (BYK E-420, manufactured by Big Chemie Japan), a carbodiimide group 5 parts by mass of a resin (Carbodilite E-05, manufactured by Nisshinbo Chemical Co., Ltd.) having a pH of 5 was added and mixed, and the coating solution concentration was adjusted to 15% by mass to obtain an undercoat layer coating solution 9.

<Preparation of undercoat layer coating solution 10>
A dispersed water solution in which 7 parts by mass of borax and 7 parts by mass of orthoboric acid were dissolved in water was obtained. Disperse 20 parts by mass of colloidal silica (Snowtex 30, manufactured by Nissan Chemical Industries, Ltd.) and 100 parts by mass of wet synthetic silica (Mizukasil P-78A, manufactured by Mizusawa Chemical Co., Ltd.) in the dispersion solution. Obtained. Next, 60 parts by mass of a styrene-butadiene resin having a carboxyl group as a binder (0695, manufactured by JSR), 2 parts by mass of a rheology control agent (BYK E-420, manufactured by BYK Japan, Inc.), carbodiimide 5 parts by mass of a group-containing resin (Carbodilite V-10, manufactured by Nisshinbo Chemical Co., Ltd.) was added and mixed, and the coating solution concentration was adjusted to 15% by mass, whereby an undercoat layer coating solution 10 was obtained.

<Preparation of undercoat layer coating solution 11>
A dispersed water solution in which 7 parts by mass of borax and 7 parts by mass of orthoboric acid were dissolved in water was obtained. Disperse 20 parts by mass of colloidal silica (Snowtex 30, manufactured by Nissan Chemical Industries, Ltd.) and 100 parts by mass of wet synthetic silica (Mizukasil P-78A, manufactured by Mizusawa Chemical Co., Ltd.) in the dispersion solution. Obtained. Next, 60 parts by mass of a urethane-based resin having a carboxyl group as a binder (Hydran WLS202, manufactured by DIC) and 2 parts by mass of a rheology control agent (BYK E-420, manufactured by Big Chemie Japan) are added to the pigment dispersion and mixed. The undercoat layer coating solution 11 was obtained by adjusting the coating solution concentration to 15% by mass.

<Preparation of undercoat layer coating solution 12>
A dispersed water solution in which 7 parts by mass of borax and 7 parts by mass of orthoboric acid were dissolved in water was obtained. Disperse 20 parts by mass of colloidal silica (Snowtex 30, manufactured by Nissan Chemical Industries, Ltd.) and 100 parts by mass of wet synthetic silica (Mizukasil P-78A, manufactured by Mizusawa Chemical Co., Ltd.) in the dispersion solution. Obtained. Next, 60 parts by mass of a styrene-butadiene resin having a carboxyl group as a binder (0695, manufactured by JSR) and 2 parts by mass of a rheology control agent (BYK E-420, manufactured by Big Chemie Japan) are added to the pigment dispersion. The mixture was mixed and the concentration of the coating solution was adjusted to 15% by mass to obtain an undercoat layer coating solution 12.

<Preparation of undercoat layer coating solution 13>
A pigment dispersion was obtained by dispersing 20 parts by mass of colloidal silica (Snowtex 30, Nissan Chemical Industries) and 100 parts by mass of wet synthetic silica (Mizukasil P-78A, Mizusawa Chemical Co., Ltd.) in water. Next, 60 parts by mass of a urethane-based resin having a carboxyl group as a binder (Hydran WLS202, manufactured by DIC), 2 parts by mass of a rheology control agent (BYK E-420, manufactured by Big Chemie Japan), a carbodiimide group 5 parts by mass of a resin (Carbodilite V-10, manufactured by Nisshinbo Chemical Co., Ltd.) having a pH of 15 was added and mixed, and the concentration of the coating solution was adjusted to 15% by mass, whereby an undercoat layer coating solution 13 was obtained.

<Preparation of undercoat layer coating solution 14>
A dispersed water solution in which 7 parts by mass of borax and 7 parts by mass of orthoboric acid were dissolved in water was obtained. 120 parts by mass of high-white kaolin (Ultra White 90, manufactured by Engelhard) was dispersed in the dispersion solution to obtain a pigment dispersion. Next, 60 parts by mass of a urethane-based resin having a carboxyl group as a binder (Hydran WLS202, manufactured by DIC), 2 parts by mass of a rheology control agent (BYK E-420, manufactured by Big Chemie Japan), a carbodiimide group 5 parts by mass of a resin (Carbodilite V-10, manufactured by Nisshinbo Chemical Co., Ltd.) was added and mixed, and the coating solution concentration was adjusted to 15% by mass, whereby an undercoat layer coating solution 14 was obtained.

<Preparation of topcoat layer coating solution 1>
Using 1.4 parts by mass of acetic acid as a dispersant, 100 parts by mass of alumina hydrate (DISPERAL HP14, manufactured by Sasol Japan) was dispersed in water to a concentration of 28% by mass to obtain a pigment dispersion. 10 parts by mass of polyvinyl alcohol (PVA235, manufactured by Kuraray Co., Ltd.) having a concentration of 8% by mass was added to the pigment dispersion, and the coating solution concentration was adjusted to 20% by mass to obtain a topcoat layer coating solution 1.

<Preparation of topcoat layer coating solution 2>
Using 0.7 parts by mass of acetic acid as a dispersant, 75 parts by mass of alumina hydrate (DISPERAL HP14, manufactured by Sasol Japan) and 25 parts by mass of wet synthetic silica (Mizukasil P-78A, manufactured by Mizusawa Chemical Co., Ltd.) have a concentration of 26. A pigment dispersion was obtained by dispersing in water to a mass%. 12.5 parts by weight of polyvinyl alcohol (PVA235, manufactured by Kuraray Co., Ltd.) having a concentration of 8% by mass was added to the pigment dispersion, and the coating solution concentration was adjusted to 20% by mass to obtain a topcoat layer coating solution 2. .

Example 1
The undercoat layer coating solution 1 was applied and dried on the absorbent support with an air knife coater so that the coating amount was 10 g / m ² , thereby providing an undercoat layer. Next, the overcoat layer coating solution 1 was applied and dried on the undercoat layer with an air knife coater so that the coating amount was 16 g / m ² , thereby providing an overcoat layer. Next, a soft calendering process was performed so that the overcoat layer hit the metal roll surface once under the conditions of a linear pressure of 20 kN / m and a speed of 5 m / min, whereby the ink jet recording material of Example 1 was obtained.

(Example 2)
An ink jet recording material of Example 2 was obtained in the same manner as in Example 1 except that the undercoat layer coating solution 1 of Example 1 was changed to the undercoat layer coating solution 2.

(Example 3)
An ink jet recording material of Example 3 was obtained in the same manner as in Example 1 except that the undercoat layer coating solution 1 of Example 1 was changed to the undercoat layer coating solution 3.

Example 4
An ink jet recording material of Example 4 was obtained in the same manner as in Example 1 except that the undercoat layer coating solution 1 of Example 1 was changed to the undercoat layer coating solution 4.

(Example 5)
An ink jet recording material of Example 5 was obtained in the same manner as in Example 1 except that the undercoat layer coating solution 1 of Example 1 was changed to the undercoat layer coating solution 5.

(Example 6)
An ink jet recording material of Example 6 was obtained in the same manner as in Example 1 except that the undercoat layer coating solution 1 of Example 1 was changed to the undercoat layer coating solution 6.

(Example 7)
An ink jet recording material of Example 7 was obtained in the same manner as in Example 1 except that the undercoat layer coating solution 1 of Example 1 was changed to the undercoat layer coating solution 7.

(Example 8)
An ink jet recording material of Example 8 was obtained in the same manner as in Example 1 except that the undercoat layer coating solution 1 of Example 1 was changed to the undercoat layer coating solution 8.

Example 9
An ink jet recording material of Example 9 was obtained in the same manner as in Example 1 except that the undercoat layer coating solution 1 of Example 1 was changed to the undercoat layer coating solution 9.

(Example 10)
An ink jet recording material of Example 10 was obtained in the same manner as in Example 1 except that the undercoat layer coating solution 1 of Example 1 was changed to the undercoat layer coating solution 10.

(Example 11)
An inkjet recording material of Example 11 was obtained in the same manner as in Example 5 except that the topcoat layer coating solution 1 of Example 5 was changed to the topcoat layer coating solution 2.

(Comparative Example 1)
An inkjet recording material of Comparative Example 1 was obtained in the same manner as in Example 1 except that the undercoat layer coating solution 1 of Example 1 was changed to the undercoat layer coating solution 11.

(Comparative Example 2)
An inkjet recording material of Comparative Example 2 was obtained in the same manner as in Example 1 except that the undercoat layer coating solution 1 of Example 1 was changed to the undercoat layer coating solution 12.

(Comparative Example 3)
An inkjet recording material of Comparative Example 3 was obtained in the same manner as in Example 1, except that the undercoat layer coating solution 1 of Example 1 was changed to the undercoat layer coating solution 13.

(Comparative Example 4)
An inkjet recording material of Comparative Example 4 was obtained in the same manner as in Example 1 except that the undercoat layer coating solution 1 of Example 1 was changed to the undercoat layer coating solution 14.

  The following tests were conducted on the ink jet recording materials of the examples and comparative examples obtained as described above. The results are shown in Table 1.

<Evaluation of coating layer strength>
An 18 mm wide mending tape (manufactured by Sumitomo 3M) is applied to the ink jet recording material, the area of the coating layer transferred to the mending tape when peeled off is visually observed, and evaluated according to the following criteria. went. In the present invention, if the evaluation is 良好 or ○, the coating layer strength is good.
A: Almost no coating layer is transferred, and the coating layer strength is good.
○: A slight coating layer is transferred, but the coating layer strength is practically acceptable.
Δ: Level at which a considerable part of the coating layer is transferred and the coating layer strength becomes a problem.
X: Level at which almost all of the coating layer is transferred and the coating layer strength becomes a serious problem.

<Evaluation of ink absorbency>
Using an ink jet recording material, Seiko Epson Inkjet Printer PX-5500 (paper type: PX proof paper <fine gloss>, print quality: super photo, bidirectional printing: on, color setting: no color correction) Printed. The ink absorptivity was evaluated according to the following criteria. The image used for the evaluation consists of black, cyan, magenta, yellow, blue, red and green color solid print images and a pattern in which white characters are incorporated in each color solid image portion. In the present invention, if the evaluation is 優 れ or ○, the ink absorbency is excellent.
(Double-circle): A blur is not recognized by each color outline part or a letter by microscopic observation (x25).
○: Slight blurring is observed in each color contour portion and extracted characters by microscopic observation (× 25).
It is hard to be recognized by visual observation, and there is no problem in actual use.
(Triangle | delta): A blur is recognized by each color outline part and a blank character by microscope observation (x25).
It is slightly recognized even by visual observation, which causes a problem in actual use.
X: Bleeding is recognized in each color outline portion and extracted characters by visual observation, which causes a problem in actual use.

<Evaluation of color development>
Black ink-jet recording material using Seiko Epson inkjet printer PX-5500 (paper type: PX proof paper <fine gloss>, print quality: super photo, bidirectional printing: on, color setting: no color correction) , Cyan, magenta, and yellow solid images were printed. The optical density of each color was measured with a portable spectrophotometer (SpectroEye, manufactured by X-Rite Co., Ltd.) and evaluated according to the following criteria based on the total optical density value of each color. The larger the optical density value, the better the color developability. In the present invention, if the evaluation is ◎ or ○, the color developability is excellent.
A: The total value of optical density is 8.5 or more.
○: The total value of optical density is 7.5 or more and less than 8.5.
(Triangle | delta): The total value of optical density is 6.5 or more and less than 7.5.
X: The total value of optical density is less than 6.5.

<Evaluation of wet heat coating layer strength>
As an evaluation of the wet heat coating layer strength, the sample was left in a forced environment (80 ° C., 95% RH) for 6 weeks and then in a room temperature environment of 23 ° C., 50% RH for 1 day. Thereafter, a mending tape having a width of 18 mm (manufactured by Sumitomo 3M Co., Ltd.) was applied to the sample, and the area of the coating layer transferred to the mending tape when peeled off was visually observed and evaluated according to the following criteria. In the present invention, if the evaluation is ◎ or ○, the wet heat coating layer strength is good.
A: Almost no coating layer is transferred, and the coating layer strength is good.
○: A slight coating layer is transferred, but there is no practical problem.
Δ: Level at which a considerable part of the coating layer is transferred and the coating layer strength becomes a problem.
X: Level at which almost all of the coating layer is transferred and the coating layer strength becomes a serious problem.

  As is apparent from the results in Table 1, it can be seen that the ink jet recording materials of Examples 1 to 11 of the present invention have good coating layer strength and wet heat coating layer strength while being excellent in ink absorbability and color developability. On the other hand, the inkjet recording materials of Comparative Examples 1 to 4 that do not satisfy the configuration of the present invention cannot obtain the effects of the present invention.

Claims (2)

  In an inkjet recording material having an absorbent support and an undercoat layer and an overcoat layer on the absorbent support, the undercoat layer is selected from a urethane resin having a carboxyl group and a styrene-butadiene resin having a carboxyl group An inkjet recording material containing at least one selected from the group consisting of a boric acid compound or a borate compound, silica, and a resin having a carbodiimide group, wherein the overcoat layer contains inorganic fine particles and polyvinyl alcohols.   2. The ink jet recording material according to claim 1, wherein at least one of the inorganic fine particles is an alumina hydrate, and the content of the alumina hydrate in the overcoat layer is more than 70% by mass with respect to the inorganic fine particles in the overcoat layer. .