JP4803662B2 - Cationic polyurethane resin-containing ink jet receiving agent and ink jet recording medium using the same - Google Patents

Description

  The present invention relates to an ink jet receiving agent that can impart good ink jet printing suitability to various substrates, is excellent in quick drying of ink, and can exhibit a high gloss finish appearance similar to a silver salt photograph. .

  In recent years, in the industry related to ink jet printing, which has been growing rapidly, the image quality of ink jet printers has been remarkably improved, and it has become possible to obtain images similar to silver halide photographs. Along with this, ink-jet recording media are also required to have ink absorptivity, high color density, blurring prevention, gloss and the like for obtaining high-definition images.

  Many ink jet recording media currently on the market generally have an ink jet receiving layer capable of exhibiting the various properties described above on a substrate made of paper, film or the like.

  The ink-jet receiving layer has a so-called microporous type in which ink penetrates into a large number of fine voids existing in the receiving layer to form an image and the like, and the resin itself present in the receiving layer absorbs ink and the like. There are so-called swelling types that form In particular, the microporous type ink jet receiving layer is superior to the ink jet receiving layer of the swelling type, and is capable of forming a high-definition image with excellent ink quick drying properties. It has been put to practical use in applications such as paper used for printing photographs.

  Examples of the ink jet receiving agent capable of forming the microporous type ink jet receiving layer include those containing water-insoluble polyurethane resin particles exhibiting a specific range of storage elastic modulus and alumina hydrate. It is known that it has excellent absorptivity, high image density, clear color tone, good image resolution, and does not cause cracking of the ink-jet receiving layer or peeling from the substrate even when it is folded. (For example, refer to Patent Document 1).

  However, since the ink jet receiving agent may cause partial aggregation of the alumina hydrate due to the interaction between the water-insoluble polyurethane resin particles and the alumina hydrate, the ink jet receiving agent is formed using the ink jet receiving agent. Furthermore, it is difficult to say that the ink jet receiving layer is sufficient in terms of glossiness and the like.

  In addition, as an ink jet receiving agent, a coating liquid containing a hydrophilic binder and inorganic fine particles is known. According to such a coating liquid, surface cracks are unlikely to occur, high gloss, water resistance, ink It is known that it is possible to form a receiving layer having excellent absorbability (see, for example, Patent Document 2).

  However, as described in Document 2, in order to form a receiving layer having a film thickness of approximately 30 μm or more using the coating solution, for example, the coating solution is applied on a support and then the coating solution is applied. It is necessary to go through a complicated and special drying process, such as cooling the surface and then drying at an elevated temperature. From the viewpoint of improving the production efficiency of the inkjet recording medium, the process for forming the receiving layer is simplified. Is desired.

  On the other hand, when the film thickness of the receiving layer is about 1/3 to 1/2 of the conventional layer, specifically about 5 to 15 μm, usually without undergoing a special drying step as described above, It becomes possible to suppress the occurrence of surface cracks in the receiving layer. However, it has been difficult to say that the thin-film receiving layer has a practically sufficient level of ink absorbability and ink quick-drying.

As described above, conventional ink jet receivers have excellent ink quick-drying characteristics that are characteristic of a microporous type, practically sufficient levels of glossiness and transparency, and cracks on the surface of the receiving layer. It has been difficult to form a thin-film ink jet receiving layer that does not easily cause such problems.
JP 2000-2111245 A Japanese Patent Laid-Open No. 10-203006

  The problem to be solved by the present invention is that even if the thickness of the ink-jet receiving layer is thinner than that of the conventional microporous type ink-jet receiving layer, the ink can be dried quickly and has a practically sufficient level. It is an object of the present invention to provide an ink jet receiving agent capable of forming an ink jet receiving layer having gloss and preventing the occurrence of surface cracks in the receiving layer.

  The present inventors proceeded with studies to solve the above problems based on an ink-jet receiving agent containing a water-soluble resin typified by polyvinyl alcohol, which has been conventionally used in ink-jet receiving agents, and the silica. .

  Specifically, an ink jet receiving agent containing various resins including a cationic resin in addition to the water-soluble resin and silica was examined. While proceeding with the investigation, when an ink-jet receiving agent containing various urethane resins conventionally known as cationic resins was examined, the ink-jet receiving layer formed by such an ink-jet receiving agent had a film thickness of the conventional one. Even when the film thickness was reduced to about 1/3 to 1/2 of the film thickness of the microporous ink jet receiving layer, it had good gloss and the like. However, the ink-jet receiving layer still does not have sufficient ink absorbability, and as a result, excellent ink quick-drying properties could not be exhibited.

  The present inventors have further investigated and, in addition to the water-soluble resin and silica, as long as the ink-jet receiving agent contains a urethane resin having a specific structure shown below as a urethane resin, the ink-jet receiving formed. It has been found that even if the layer is a thin film, excellent ink absorbability and quick ink drying can be achieved without impairing various physical properties such as gloss.

That is, the present invention is an aqueous medium, a cationic polyurethane resin (B) containing a structural unit (A) represented by the following general formula [I] in a molecule dispersed in the aqueous medium, and dispersed in the aqueous medium. It contains dry silica (C) and a water-soluble resin (D), and the content of the cationic amino group contained in the structural unit (A) in the cationic polyurethane resin (B) is 0.005. After coating or impregnating the base material with an ink jet receiving agent characterized by an amount of ˜1.5 equivalent / kg, the water-based medium is volatilized so that the ink jet receiving layer having a thickness of 5 μm to 15 μm is formed on the base material. The present invention provides a microporous ink jet recording medium formed thereon .

〔式中、Ｒ₁は、脂肪族環式構造を含んでいてもよいアルキレン基、２価フェノール類の残基、又はポリオキシアルキレン基を、Ｒ_２及びＲ_３は、互いに独立して脂肪族環式構造を含んでいてもよいアルキル基を、Ｒ_４は、水素原子又は４級化反応により導入された４級化剤の残基を、Ｘ⁻はアニオン性の対イオンを表す。〕

[Wherein, R ₁ represents an alkylene group that may contain an aliphatic cyclic structure, a residue of a dihydric phenol, or a polyoxyalkylene group, and R ₂ and R ₃ independently represent an aliphatic group. An alkyl group which may contain a cyclic structure, R ₄ represents a hydrogen atom or a residue of a quaternizing agent introduced by a quaternization reaction, and X ⁻ represents an anionic counter ion. ]

  Furthermore, the present invention provides an ink jet receiving agent in which an ink jet receiving layer is formed on the substrate by volatilizing the aqueous medium after coating or impregnating the ink jet receiving agent on the substrate. .

  The ink jet receiving agent of the present invention has excellent quick-drying and practically sufficient level of gloss even when the ink jet receiving layer is thinner than the conventional microporous type ink jet receiving layer. The inkjet recording medium having the inkjet receiving layer formed by the inkjet receiving agent of the present invention was photographed with a digital camera because the inkjet receiving layer having the inkjet receiving layer of the present invention can be prevented. It can be used for various purposes such as paper used for printing photographs and the like.

  The inkjet receiver of the present invention includes an aqueous medium, a cationic polyurethane resin (B) containing a structural unit (A) represented by the following general formula [I] in a molecule dispersed in the aqueous medium, and the aqueous medium. The silica (C) dispersed in the water and the water-soluble resin (D) are contained, and the content of the cationic amino group contained in the structural unit (A) in the cationic polyurethane resin (B) is 0. The present invention provides an ink jet receiving agent characterized in that the amount is 0.005 to 1.5 equivalent / kg.

  First, the aqueous medium constituting the ink jet receiving agent of the present invention is water and an organic solvent miscible with water. Examples of organic solvents miscible with water include alcohols such as methanol, ethanol, n- and isopropanol; ketones such as acetone and methyl ethyl ketone; polyalkylene glycols such as ethylene glycol, diethylene glycol and propylene glycol; Alkyl ethers; Amides such as N-methyl-2-pyrrolidone, etc. can be used. In the present invention, only water or a mixture of water and an organic solvent miscible with water may be used. From the viewpoint of safety and environmental load, water alone or a mixture of water and an organic solvent miscible with water is preferred, and water alone is particularly preferred.

Next, the cationic polyurethane resin (B) used in the present invention will be described.
The cationic polyurethane resin (B) used in the present invention contains a structural unit (A) represented by the following general formula [I] in the molecule, and the cationic amino resin contained in the structural unit (A). A group is contained in the cationic polyurethane resin (B) in an amount of 0.005 equivalents / kg to 1.5 equivalents / kg.

[Wherein, R ₁ represents an alkylene group that may contain an aliphatic cyclic structure, a residue of a dihydric phenol, or a polyoxyalkylene group, and R ₂ and R ₃ independently represent an aliphatic group. An alkyl group which may contain a cyclic structure, R ₄ represents a hydrogen atom or a residue of a quaternizing agent introduced by a quaternization reaction, and X ⁻ represents an anionic counter ion. ]

  The structural unit (A) represented by the general formula [I] is an essential structural unit for imparting dispersibility to an aqueous medium to the cationic polyurethane resin (B) constituting the present invention. The structural unit (A) represented by the general formula [I] is an essential structural unit for improving the miscibility between the cationic polyurethane resin (B) and the silica (C). The ink jet receiving agent having improved miscibility can form an ink jet receiving layer having no surface cracks and excellent film-forming properties and gloss.

  The cationic polyurethane resin (B) used in the present invention can be produced by using a known compound. As a production method using an industrially easily available and inexpensive raw material, the following general formula [II A tertiary amino group-containing polyol (E) obtained by reacting a compound (A-1) having two epoxy groups in one molecule with a secondary amine (A-2), The method of reacting with isocyanate (G) is most useful.

[Wherein, R ₁ represents an alkylene group which may include an aliphatic cyclic structure, a residue of a dihydric phenol, or a polyoxyalkylene group. ]
The tertiary amino group-containing polyol (E) is a precursor for generating a cationic group by neutralizing the tertiary amino group contained in the molecule with an acid or quaternizing with a quaternizing agent. Yes, it is a compound for imparting water dispersibility to the polyurethane resin.

  The tertiary amino group-containing polyol (E) includes, for example, a compound (A-1) having two epoxy groups in one molecule and a secondary amine (A-2) with NH equivalent to one equivalent of epoxy group. It can be easily obtained by blending so as to be 1 equivalent of a group and performing a ring-opening addition reaction at room temperature or under heating without using a catalyst.

  As the compound (A-1) having two epoxy groups in one molecule represented by the general formula [II], the following compounds may be used alone or in combination of two or more.

Examples of the group in which R ₁ is an alkylene group which may contain an aliphatic cyclic structure include ethanediol-1,2-diglycidyl ether, propanediol-1,2-diglycidyl ether, propanediol- 1,3-diglycidyl ether, butanediol-1,4-diglycidyl ether, pentanediol-1,5-diglycidyl ether, 3-methyl-pentanediol-1,5-diglycidyl ether, neopentyl glycol-di Of glycidyl ether, hexanediol-1,6-diglycidyl ether, polybutadiene-diglycidyl ether, cyclohexane-1,4-diglycidyl ether, 2,2-bis (4-hydroxycyclohexyl) -propane (hydrogenated bisphenol A) Diglycidyl ether, hydrogen Diglycidyl ether of (hydrogenated bisphenol F), which is an isomer mixture of added dihydroxydiphenylmethane, can be used.

Examples of those in which R ₁ is a residue of a dihydric phenol include, for example, resorcinol-diglycidyl ether, hydroquinone-diglycidyl ether, 2,2-bis (4-hydroxyphenyl) -propane (bisphenol A) Diglycidyl ether, diglycidyl ether of isomer mixture of dihydroxydiphenylmethane (bisphenol F), diglycidyl ether of 4,4-dihydroxy-3,3′-dimethyldiphenylpropane, diglycidyl ether of 4,4-dihydroxydiphenylcyclohexane, 4 , 4-dihydroxydiphenyl diglycidyl ether, 4,4-dihydroxydibenzophenone diglycidyl ether, bis (4-hydroxyphenyl) -1,1-ethane diglycidyl ether, bis (4-hydroxy Phenyl) -1,1-isobutane diglycidyl ether, bis (4-hydroxy-3-tert-butylphenyl) -2,2-propane diglycidyl ether, bis (2-hydroxynaphthyl) methane diglycidyl ether, Diglycidyl ether of bis (4-hydroxyphenyl) sulfone (bisphenol S) or the like can be used.

Examples of the group in which R ₁ is a polyoxyalkylene group include diethylene glycol-diglycidyl ether, dipropylene glycol-diglycidyl ether, and polyoxyalkylene glycol-diglycidyl ether having 3 to 60 repeating units of oxyalkylene. For example, polyoxyethylene glycol-diglycidyl ether and polyoxypropylene glycol-diglycidyl ether, diglycidyl ether of ethylene oxide-propylene oxide copolymer, polyoxytetraethylene glycol-diglycidyl ether, etc. can be used. .

Among these, since the water dispersibility of the cationic polyurethane resin (B) can be further improved, diglycidyl ether of polyoxyalkylene glycol in which R ₁ of the general formula [II] is a polyoxyalkylene group, In particular, polyoxyethylene glycol-diglycidyl ether and / or polyoxypropylene glycol-diglycidyl ether and / or diglycidyl ether of ethylene oxide-propylene oxide copolymer are suitable.

The epoxy equivalent of the diglycidyl ether of polyoxyalkylene glycol in which R _{1 in the} general formula [II] is a polyoxyalkylene group affects the physical properties such as various mechanical properties and thermal properties of the inkjet receiver of the present invention. Is preferably 1000 g / equivalent or less, more preferably 500 g / equivalent or less, particularly preferably 300 g / equivalent in that the cationic concentration in the cationic polyurethane resin (B) aqueous dispersion can be designed over a wide range. It is below the equivalent.

  In the present invention, in order to produce a tertiary amino group-containing polyol (E) by a ring-opening addition reaction with a compound (A-1) having two epoxy groups in one molecule, a secondary amine (A-2 )is required.

As the secondary amine (A-2), a known compound can be used, but a branched or linear aliphatic secondary amine is preferable from the viewpoint of easy reaction control.
Examples of such secondary amine that can be used include dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine, di-tert-butylamine, di-sec-butylamine, di-n. -Pentylamine, di-n-heptylamine, di-n-hexylamine, di-n-octylamine, diisooctylamine, dinonylamine, diisononylamine, di-n-decylamine, di-n-undecylamine, di- -N-dodecylamine, di-n-pentadecylamine, di-n-octadecylamine, di-n-nonadecylamine, di-n-eicosylamine and the like.

  Among these, it is difficult to volatilize when producing the tertiary amino group-containing polyol (E), or part or all of the tertiary amino group contained is neutralized with an acid, or 4 with a quaternizing agent. For reasons such as the ability to reduce steric hindrance when classifying, an aliphatic secondary amine having 2 to 18 carbon atoms is preferred, and an aliphatic secondary amine having 3 to 8 carbon atoms is more preferred.

  A tertiary amino group-containing polyol (E) is obtained by neutralizing part or all of the tertiary amino group of the tertiary amino group-containing polyol (E) with an acid or quaternizing with a quaternizing agent. Water dispersibility can be imparted to the cationic polyurethane resin (B) obtained by reacting with the polyisocyanate (G).

  Examples of the acid that can be used for neutralizing part or all of the tertiary amino group include formic acid, acetic acid, propionic acid, succinic acid, glutaric acid, butyric acid, lactic acid, malic acid, and citric acid. , Organic acids such as tartaric acid, malonic acid, adipic acid, organic sulfonic acids such as sulfonic acid, paratoluenesulfonic acid, methanesulfonic acid, and hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, boric acid, phosphorous acid, hydrofluoric acid Inorganic acids such as can be used. These acids may be used alone or in combination of two or more.

Examples of the quaternizing agent that can be used for quaternizing a part or all of the tertiary amino group include dialkyl sulfates such as dimethyl sulfate and diethyl sulfate, methyl chloride, and ethyl chloride. Alkyl halides such as benzyl chloride, methyl bromide, ethyl bromide, benzyl bromide, methyl iodide, ethyl iodide, benzyl iodide, and alkyl or aryl sulfonates such as methyl methanesulfonate and methyl paratoluenesulfonate Epoxy such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, allyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, and phenyl glycidyl ether It is possible to use kind and the like.
These may be used alone or in combination of two or more.

  In the present invention, the amount of acid or quaternizing agent used for neutralization or quaternization of the tertiary amino group is not particularly limited, but the ink-jet receiving agent of the present invention exhibits excellent water resistance of the printed image. Therefore, it is preferably in the range of 0.1 equivalents to 2.0 equivalents, more preferably in the range of 0.3 equivalents to 1.0 equivalents with respect to 1 equivalent of the tertiary amino group.

  In the ink jet receiving agent of the present invention, the cationic polyurethane resin (B) is quaternized with a tertiary amino group from the viewpoint that the fixing property of the ink jet ink is excellent, and as a result, the water resistance of the printed image is further improved. More preferably.

A method for reacting the compound (A-1) having two epoxy groups in one molecule with the secondary amine (A-2) for obtaining the tertiary amino group-containing polyol (E) will be described below.
The reaction ratio [NH group / epoxy group] of the epoxy group of the compound (A-1) having two epoxy groups in one molecule and the NH group of the secondary amine (A-2) is preferably equivalent. The ratio is in the range of 0.5 / 1 to 1.1 / 1, more preferably the equivalent ratio is in the range of 0.9 / 1 to 1/1.

  These reactions can be carried out under solvent-free conditions, but can also be carried out using an organic solvent for the purpose of facilitating reaction control, or for the purpose of reducing the stirring load due to viscosity reduction or causing the reaction to be uniform. .

  Such an organic solvent may be any organic solvent that does not inhibit the reaction. For example, ketones, ethers, acetate esters, hydrocarbons, chlorinated hydrocarbons, amides, and nitriles can be used. .

As said ketones, acetone, diethyl ketone, methyl ethyl ketone, methyl isobutyl ketone etc. can be used, for example.
Examples of ethers that can be used include diethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, tetrahydrofuran, and dioxane.

Examples of the acetates include ethyl acetate, butyl acetate, propyl acetate and the like.
As hydrocarbons, n-pentane, n-hexane, cyclohexane, n-heptane, benzene, toluene, xylene and the like can be used.
As chlorinated hydrocarbons, for example, carbon tetrachloride, dichloromethane, chloroform, trichloroethane and the like can be used.
As amides, for example, dimethylformamide, N-methyl-2-pyrrolidone, and as nitriles, for example, acetonitrile can be used.

  The compound (A-1) having two epoxy groups in one molecule and the secondary amine (A-2) may be supplied together and reacted in a reaction vessel, and an epoxy group is contained in one molecule. Any one of the two compounds (A-1) and the secondary amine (A-2) may be charged into a reaction vessel and the other may be dropped.

  Since the reaction between the compound (A-1) having two epoxy groups in one molecule and the secondary amine (A-2) is highly reactive, it usually does not require a catalyst. However, when the secondary amine (A-2) has a large substituent such as an aliphatic nitrogen atom, and the reaction with the compound (A-1) is slowed by steric hindrance, phenol, acetic acid, water A proton donating substance typified by alcohols may be used as a catalyst.

The reaction temperature is preferably in the range of room temperature to 160 ° C, more preferably in the range of 60 ° C to 120 ° C.
The reaction time is not particularly limited, but is usually in the range of 30 minutes to 14 hours.
The end point of the reaction can be confirmed by disappearance of the absorption peak near 842 cm ⁻¹ due to the epoxy group by infrared spectroscopy (IR method).
Moreover, an amine equivalent (g / equivalent) and a hydroxyl equivalent (g / equivalent) can be calculated | required by a conventional method.

  When producing the cationic polyurethane resin (B), in addition to the tertiary amino group-containing polyol (E), various polyols (F) generally used for synthesis of polyurethane depending on the purpose and application. Can be used.

  Among them, the polyester polyol, polyether polyol, carbonic acid and aliphatic polyhydric alcohol having a number average molecular weight of 200 to 10,000, more preferably a number average molecular weight of 300 to 5,000 are preferably esterified. Various polyols such as polycarbonate polyol, polyesteramide polyol, polyacetal polyol, polythioether polyol, and polybutadiene glycol polyol obtained by the above-mentioned method may be used, and these may be used alone or in combination of two or more.

  Among the polyols (F), representative compounds are exemplified below for polyester polyols, polyether polyols, and polycarbonate polyols that are industrially easily available.

  As said polyester polyol, what is obtained by esterifying a low molecular weight polyol and polycarboxylic acid can be used.

  Examples of the low molecular weight polyol include ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, and 3-methyl-1,5. -Pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, polyethylene glycol (Number average molecular weight 300-6000 range), polypropylene glycol (number average molecular weight 300-6000 range), ethylene oxide-propylene oxide copolymer (number average molecular weight 300-6000) Circumference); bisphenol A, hydrogenated bisphenol A and alkylene oxide adducts thereof; trimethylolpropane, trimethylolethane, pentaerythritol, it can be used sorbitol.

  Examples of the polycarboxylic acid that can be used in producing the polyester polyol include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic anhydride, fumaric acid, 1,3-cyclopentanedicarboxylic acid, 1 , 4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, 1,2-bis (phenoxy) ethane-p , P′-dicarboxylic acid, trimellitic acid, pyromellitic acid, and anhydrides or ester-forming derivatives of these polycarboxylic acids can be used.

  Moreover, as said polyester polyol, polyester obtained by ring-opening polymerization reaction of cyclic ester compounds, such as (epsilon) -caprolactone, these copolyesters, etc. can also be used.

  In addition, as the polyether polyol, for example, a compound having at least two active hydrogen atoms described later is used as an initiator, and one or more compounds such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, and tetrahydrofuran are added. Those obtained by polymerization can be used.

  Examples of the compound having at least two active hydrogen atoms include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and hexamethylene glycol. , Saccharose, glycerin, sorbitol; actinic acid, trimellitic acid, hemimellitic acid, phosphoric acid, ethylenediamine, propylenediamine, diethylenetriamine, triisopropanolamine, pyrogallol, dihydrobenzoic acid, hydroxyphthalic acid, 1,2,3-propanetri Thiols and the like can be used.

  Examples of the polycarbonate polyol obtained by esterifying carbonic acid with an aliphatic polyhydric alcohol include 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6. -Diols such as hexanediol, diethylene glycol, polyethylene glycol, polypropylene glycol or polytetramethylene glycol (PTMG) and cyclic such as represented by dialkyl carbonate or ethylene carbonate represented by dimethyl carbonate A reaction product with carbonate is exemplified.

  In the ink jet receiving layer formed by the ink jet receiving agent of the present invention, since long-term storage durability is required, it is preferable to use a highly durable polyol among the polyols (F), Particularly preferred is polycarbonate polyol.

  Examples of the polyisocyanate (G) that can be used in producing the cationic polyurethane resin (B) of the present invention include aqueous polyurethane resins such as aromatic polyisocyanates, alicyclic polyisocyanates, and aliphatic polyisocyanates. And known organic polyisocyanates used in the production of

  Examples of the polyisocyanate include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 2 , 2'-diphenylmethane diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenylene diisocyanate, 3,3'-dichloro-4,4'-biphenylene Diisocyanate, 1,5-naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, dodecamethylene diisocyanate Trimethylhexamethylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, hydrogenated xylylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, 4,4'- Dicyclohexylmethane diisocyanate, 3,3′-dimethyl-4,4′-dicyclohexylmethane diisocyanate, and trimers thereof can be used.

  Since the ink-jet receiving layer formed by the ink-jet receiving agent of the present invention is required to have long-term storage durability, it is necessary to prevent deterioration of the surface appearance due to heat discoloration and light discoloration. For this reason, it is preferable to use alicyclic polyisocyanate and / or aliphatic polyisocyanate which are generally called non-yellowing type as polyisocyanate (G).

  From this point, considering the availability of raw materials, the polyisocyanate (G) is 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 4,4′-dicyclohexylmethane diisocyanate, 2 It is particularly preferred to use 4,4'-dicyclohexylmethane diisocyanate, 2,2'-dicyclohexylmethane diisocyanate.

  When the cationic polyurethane resin (B) is produced, polyamine may be used as a chain extender for the purpose of designing a polyurethane resin having physical properties such as various mechanical properties and thermal properties.

  Examples of the polyamine that can be used as the chain extender include ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, isophoronediamine, and 4,4′-dicyclohexylmethane. Diamines such as diamine, 3,3′-dimethyl-4,4′-dicyclohexylmethanediamine, 1,4-cyclohexanediamine; N-hydroxymethylaminoethylamine, N-hydroxyethylaminoethylamine, N-hydroxypropylaminopropylamine Diamines containing hydroxyl groups such as, diethylenetriamine, dipropylenetriamine, triethylenetetramine, N-ethylaminoethylamine, N-methylaminopropylamine and other polyamines; hydrazine, N, N Hydrazines such as dimethylhydrazine and 1,6-hexamethylenebishydrazine; dihydrazides such as succinic acid dihydrazide, adipic acid dihydrazide, glutaric acid dihydrazide, sebacic acid dihydrazide, and isophthalic acid dihydrazide; Semicarbazides such as semicarbazide-propyl-carbazate, semicarbazide-3-semicarbazidemethyl-3,5,5-trimethylcyclohexane can be used.

  When the cationic polyurethane resin (B) is produced, in addition to the polyamine, other chain extenders containing active hydrogen atoms are used for the purpose of adjusting physical properties such as various mechanical properties and thermal properties of the polyurethane resin. Can also be used.

  Examples of the other active hydrogen-containing chain extender include, for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4 -Glycols such as butanediol and hexamethylene glycol; phenols such as bisphenol A, 4,4'-dihydroxydiphenyl, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl sulfone, hydrogenated bisphenol A, hydroquinone And their alkylene oxide adducts, polyhydroxy compounds such as glycerin, trimethylolpropane, sorbitol, and water, and lower the storage stability of the aqueous dispersion of the cationic polyurethane resin of the present invention. It may be alone or in combination of these within a range that does not let.

  Furthermore, the ink jet receiving agent of the present invention is a cationic polyurethane resin in which the structural unit (H) represented by the following general formula [III] is represented by a cationic polyurethane resin for the purpose of developing a further excellent binder force with respect to silica (C). It is preferable to introduce into the skeleton of (B).

(In the formula, R ₅ is a monovalent organic residue selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group and an aralkyl group, and R ₆ is a halogen atom, an alkoxyl group, an acyloxy group, a phenoxy group, an iminooxy group) A functional group selected from the group consisting of a group or an alkenyloxy group, and n represents an integer of 0, 1 or 2.)

  As a compound for introducing the structural unit (H) into the cationic polyurethane resin (B), a compound (I) represented by the following general formula [IV] is preferable.

(In the formula, R ₅ is a monovalent organic residue selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group and an aralkyl group, and R ₆ is a halogen atom, an alkoxyl group, an acyloxy group, a phenoxy group, an iminooxy group) A functional group selected from the group consisting of a group or an alkenyloxy group, n represents an integer of 0, 1 or 2, and Y represents an organic residue containing at least one amino group.)

  Examples of compounds that can be used as the compound represented by the general formula [III] include γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-hydroxyethyl) aminopropyltrimethoxysilane, γ -(2-aminoethyl) aminopropyltriethoxysilane, γ- (2-hydroxyethyl) aminopropyltriethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxyaminopropylmethyldimethoxysilane, γ- (2- Aminoethyl) aminopropylmethyldiethoxysilane, γ- (2-hydroxyethyl) aminopropylmethyldimethoxysilane, γ- (2-hydroxyethyl) aminopropylmethyldiethoxysilane or γ- (N, N-di-2- Hydroxyethyl) aminopropyltriethoxy Γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, or γ- (N-phenyl) aminopropyltrimethoxysilane, etc. Can be mentioned.

  Examples of the method for producing the cationic polyurethane resin (B) used in the present invention and dispersing the cationic polyurethane resin (B) in the aqueous medium include the following methods.

[Method 1] A polyurethane resin is produced by charging a polyol (F), a polyisocyanate (G), and a tertiary amino group-containing polyol (E) all at once or separately and reacting them in a solvent or in the absence of a solvent. A method in which part or all of the tertiary amino groups in the obtained polyurethane resin are neutralized with an acid and / or quaternized with a quaternizing agent, and then water is added to disperse in water.

[Method 2] A polyol (F), a polyisocyanate (G), and a tertiary amino group-containing polyol (E) are charged all at once or separately and reacted in a solvent or in the absence of a solvent to form an isocyanate group at the terminal. After producing a urethane prepolymer having a polyurethane resin, a polyurethane resin is produced by chain extension using a polyamine, and some or all of the tertiary amino groups in the obtained polyurethane resin are neutralized with an acid, and / or 4 A method in which water is added and dispersed after quaternization with a classifier.

[Method 3] A polyol (F), a polyisocyanate (G), and a tertiary amino group-containing polyol (E) are charged all at once or separately, and reacted in a solvent or in the absence of a solvent to form an isocyanate group at the terminal. The urethane prepolymer is produced, and part or all of the tertiary amino groups in the obtained urethane prepolymer are neutralized with an acid and / or quaternized with a quaternizing agent, and then water is added thereto. A method in which water is dispersed and then chain elongation is performed using polyamine.

[Method 4] Polyol (F), polyisocyanate (G), and tertiary amino group-containing polyol (E) are batched or divided and charged, and reacted in a solvent or in the absence of a solvent to react with isocyanate at the end. After producing a urethane prepolymer having a group and neutralizing a part or all of the tertiary amino group with an acid and / or quaternizing with a quaternizing agent, using a machine such as a homogenizer in an aqueous medium A method of forcibly emulsifying and dispersing in water, followed by chain elongation using polyamine.

[Method 5] A polyurethane resin is produced by charging a polyol (F), a polyisocyanate (G), a tertiary amino group-containing polyol (E) and a polyamine in a lump and reacting them in a solvent or without a solvent. A method in which part or all of the tertiary amino groups in the obtained polyurethane resin are neutralized with an acid and / or quaternized with a quaternizing agent, and then water is added to disperse in water.

  In addition, in the manufacturing method of said [Method 1]-[Method 5], you may use an emulsifier as needed.

  Although it does not specifically limit as an emulsifier which can be used when manufacturing the said cationic polyurethane resin (B) aqueous dispersion, From a viewpoint of maintaining the outstanding storage stability of the said cationic polyurethane resin (B) aqueous dispersion. Basically, it is preferably nonionic or cationic. For example, nonionic emulsifiers such as polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene styryl phenyl ether, polyoxyethylene sorbitol tetraoleate, polyoxyethylene / polyoxypropylene copolymer; alkylamine salts, It is preferable to use cationic emulsifiers such as alkyltrimethylammonium salts and alkyldimethylbenzylammonium salts. An anionic or amphoteric emulsifier may be used in combination as long as the mixing stability of the emulsifier to the cationic polyurethane resin (B) aqueous dispersion is maintained.

  When the cationic polyurethane resin (B) is produced by the above-described method, a compound having a group capable of becoming a hydrophilic group (hereinafter referred to as a hydrophilic group-containing compound) is used as an aid for assisting the water dispersibility of the resin. May be.

  As such a hydrophilic group-containing compound, an anionic group-containing compound, a cationic group-containing compound, an amphoteric group-containing compound, or a nonionic group-containing compound can be used, but the excellent storage stability of the cationic polyurethane resin aqueous dispersion is excellent. From the viewpoint of maintaining the properties, a nonionic group-containing compound is preferable.

  The nonionic group-containing compound includes a group having at least one active hydrogen atom in the molecule and consisting of a repeating unit of ethylene oxide, and a group consisting of a repeating unit of ethylene oxide and another repeating unit of alkylene oxide. A compound having at least one functional group selected from the group can be used.

  For example, polyoxyethylene glycol or polyoxyethylene-polyoxypropylene having a number average molecular weight of 300 to 20,000 containing at least 30% by mass of repeating units of ethylene oxide and containing at least one active hydrogen atom in the polymer Nonionic group-containing compounds such as copolymer glycols, polyoxyethylene-polyoxybutylene copolymer glycols, polyoxyethylene-polyoxyalkylene copolymer glycols or monoalkyl ethers thereof, or polyester polys obtained by copolymerizing these It is possible to use compounds such as ether polyols.

  Next, the raw material charging ratio (equivalent ratio) when producing the cationic polyurethane resin (B) will be described in detail.

  When the polyol (F), the tertiary amino group-containing polyol (E), and the polyisocyanate (G) are reacted, the equivalent ratio of the isocyanate group and the active hydrogen atom-containing group [equivalent of the isocyanate group possessed by (G)] / [Equivalent hydroxyl group of (F) + Equivalent hydroxyl group of (E)] is preferably adjusted to a range of 0.9 / 1 to 1.1 / 1.

  When the cationic polyurethane resin (B) is produced, for example, when a polyamine is used as a chain extender, the equivalent ratio of isocyanate group to active hydrogen atom-containing group [(equivalent of isocyanate of (G)] / [(F The equivalent of the hydroxyl group possessed by (E) + the equivalent of the hydroxyl group possessed by (E) + the equivalent of the amino group possessed by the polyamine] is preferably adjusted in the range of 0.9 / 1 to 1.1 / 1.

  Moreover, you may manufacture the said cationic polyurethane resin (B) by making chain | strand extension reaction using a polyamine, after manufacturing a urethane prepolymer. In this case, the equivalent ratio of the isocyanate group to the active hydrogen atom-containing group [equivalent of isocyanate group possessed by (G)] / [equivalent of hydroxyl group possessed by (F) + equivalent hydroxyl group possessed by (E)] It is preferable to adjust to the range of 1/1 to 3/1, and it is more preferable to adjust to the range of 1.2 / 1 to 2/1. In this case, the equivalent ratio of the amino group and excess isocyanate group of the polyamine when chain-extending with the polyamine is preferably in the range of 1.1 / 1 to 0.9 / 1.

  In such a reaction, the reaction temperature is preferably in the range of 20 ° C to 120 ° C, more preferably in the range of 30 ° C to 100 ° C.

  The tertiary amino group-containing polyol (E) is an essential structural unit for producing an ink jet recording medium having no cracks in order to improve glossiness of the ink jet recording medium. The content of the cationic amino group derived from (E) is preferably in the range of 0.005 equivalent / kg to 1.5 equivalent / kg, more preferably 0, relative to the cationic polyurethane resin (B). 0.03 equivalent / kg to 1.0 equivalent / kg, even more preferably in the range of 0.15 equivalent / kg to 0.5 equivalent / kg.

The cationic polyurethane resin (B) can be produced under solvent-free conditions, but for the purpose of facilitating the reaction control, or for the purpose of reducing the stirring load due to a decrease in viscosity or causing a uniform reaction, under an organic solvent. It is also possible to manufacture with.
Examples of the organic solvent include ketones such as acetone, diethyl ketone, methyl ethyl ketone, and methyl isobutyl ketone; ethers such as diethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, tetrahydrofuran, and dioxane; ethyl acetate Acetic esters such as butyl acetate and propyl acetate; Nitriles such as acetonitrile; Hydrocarbons such as n-pentane, n-hexane, cyclohexane, n-heptane, benzene, toluene and xylene; Carbon tetrachloride, dichloromethane and chloroform Chlorinated hydrocarbons such as trichloroethane; amides such as dimethylformamide and N-methylpyrrolidone can be used.

  The cationic polyurethane resin (B) can be produced without a catalyst, but known catalysts such as stannous octylate, dibutyltin dilaurate, dibutyltin dimaleate, dibutyltin diphthalate, dibutyltin dimethoxide Tin compounds such as dibutyltin diacetylacetate and dibutyltin diversate, titanate compounds such as tetrabutyl titanate, tetraisopropyl titanate and triethanolamine titanate, other tertiary amines, quaternary ammonium salts and the like may be used.

  The organic solvent contained in the cationic polyurethane resin aqueous dispersion obtained as described above is preferably removed by, for example, a method such as heating under reduced pressure during the reaction or after the completion of the reaction.

  Next, silica (C), which is another important material used in the present invention, will be described.

  Examples of the silica (C) include dry silica, wet silica, and sol-gel silica. Hereinafter, a method for producing these silicas will be described.

The dry silica can generally be produced by burning silicon tetrachloride. Dry silica is also commonly referred to as fumed silica.
As said dry silica, what has a specific surface area of the range of about 50-500 m < ² > / g can be used. The primary particle diameter of dry silica calculated from the specific surface area is about 5 to 50 nm, but usually forms a particle diameter of 1 μm or more in which they aggregate.

  Moreover, as said wet silica, what is called precipitation method silica and gel method silica can be used, for example.

  The precipitated silica is generally referred to as white carbon, and can be produced, for example, by neutralizing sodium silicate with a mineral acid.

The gel silica can be produced by neutralizing sodium silicate with an acid.
The various wet silicas obtained by the above method may be filtered, washed and dried after neutralization, and may be pulverized as necessary.

As said wet silica, what has a specific surface area of the range of about 50-1000 m < ² > / g can be used. The primary particle diameter of wet silica calculated from the specific surface area is about 3 to 50 nm, but usually when they aggregate to form particles having an average particle diameter of about 1 to several hundred μm There is.

  The sol-gel silica can be produced by hydrolyzing an alkoxysilane such as tetramethoxysilane or tetraethoxysilane.

  As the sol-gel method silica, bulk silica may be used, but if necessary, it may be pulverized and amorphous silica having a particle diameter of about 1 to several hundred μm may be used. Good.

As the silica (C) used in the present invention, dry silica having a specific surface area in the range of 70 to 300 m ² / g produced by burning silicon tetrachloride is used among the various types of silica described above. It is preferable for producing an ink jet receiving agent capable of forming an ink jet receiving layer having excellent gloss.

Among these, in order to form an ink jet receiving agent excellent in gloss and film forming property, it is preferable to use dry silica having a specific surface area of 70 to 100 m ² / g.

  When the inkjet receiver of the present invention is produced by the method described later, it is preferable to use the silica (C) dispersed in an aqueous medium in advance and the cationic polyurethane resin (B) and the water-soluble material. It is preferable because mixing with the functional resin (D) is easier.

Examples of the aqueous medium that can be used for dispersing the silica (C) include polar solvents such as water and organic solvents that are miscible with water. Examples of the organic solvent miscible with water include alcohols such as methanol, ethanol, n- and isopropanol; ketones such as acetone and methyl ethyl ketone; polyalkylene glycols such as ethylene glycol, diethylene glycol and propylene glycol; propylene glycol monomethyl ether; Alkyl ethers of polyalkylene glycols such as tetraethylene glycol monobutyl ether, and acetates thereof; amides such as N-methyl-2-pyrrolidone can be used.
As the aqueous medium, only water may be used, or a mixture of water and an organic solvent miscible with water may be used. As the aqueous medium, it is preferable to use only water or a mixture of water and an organic solvent miscible with water from the viewpoint of safety and environmental load, and it is particularly preferable to use only water.

  When the silica (C) is dispersed in the aqueous medium, it is preferable to disperse the silica (C) using a cationic resin in order to improve the dispersion stability of the silica (C) and to improve the fixing property of the ink. The dispersed particle diameter of the silica (C) dispersed in the aqueous medium is preferably 5 to 200 nm for forming a highly glossy ink jet receiving layer. The dispersed particle diameter is a particle diameter obtained by measuring the silica dispersion by measurement with a laser light scattering particle size distribution measuring apparatus.

  The cationic resin is not limited as long as it is a resin that dissociates and exhibits cationic properties when dissolved in an aqueous medium. For example, polyethyleneimine, polyvinylpyridine, polyaminesulfone, polyvinylamidine, polydialkylamino Ethyl methacrylate, polydialkylaminoethyl acrylate, polydialkylaminoethyl methacrylamide, polydialkylaminoethyl acrylamide, polyepoxyamine, polyamidoamine, dicyandiamide-formalin condensate, dicyandiamide polyalkyl-polyalkylene polyamine condensate, polyvinylamine, polyallylamine And their hydrochlorides, and polydiallyldimethylammonium chloride and copolymers thereof such as acrylamide, polydiallyl Ethylamine hydrochloride, a primary to tertiary amine group or a resin having a quaternary ammonium base such as polymethacrylate methyl chloride quaternary salt may be used.

  The aqueous dispersion of silica (C) can be produced, for example, by mixing and stirring silica (C) and a cationic resin in the aqueous medium.

  When using the above-mentioned cationic resin when preparing the aqueous dispersion of silica (C), 1 to 50 parts by weight of the cationic resin is used with respect to 100 parts by weight of the silica (C). It is preferable to use 1 to 10 parts by weight.

  Next, the water-soluble resin (D), which is another important material used in the present invention, will be described.

  The water-soluble resin (D) is a resin that can take a form completely dissolved in water. For example, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl acetal, polyalkylene oxide, starch, methyl cellulose, hydroxy cellulose, hydroxypropyl cellulose, hydroxypropyl Cellulose derivatives such as methylcellulose and carboxymethylcellulose, polyethyleneimine, polyamide, various quaternary ammonium base-containing water-soluble resins, and modified products thereof can be used. As the water-soluble resin (D), it is particularly preferable to use polyvinyl alcohol because the binder strength with respect to the silica (C) is particularly good and the occurrence of surface cracks in the formed inkjet receiving layer can be suppressed. .

  The polyvinyl alcohol has the physical properties necessary for an ink jet receiving agent, such as transparency, film strength, and binder power to pigments, and is readily available and has a wide variety of modified products. Traditionally used in the receiving agent industry.

  Polyvinyl alcohol is generally obtained by hydrolyzing an acetyl group portion of a vinyl acetate polymer with a strong base such as sodium hydroxide to form a hydroxyl group (saponification). As polyvinyl alcohol, those having various saponification ratios (saponification degree) and those having various polymerization degrees are commercially available. As the water-soluble resin (D), polyvinyl alcohol having a saponification degree in the range of 80 mol% to 95 mol% is preferably used from the viewpoint of suppressing surface cracking of the ink jet receiving layer, and 85 mol% to 90 mol. More preferably, polyvinyl alcohol having a saponification degree in the range of mol% is used.

  Specific examples of the polyvinyl alcohol having a saponification degree of 80 to 95 mol% include PVA224, PVA235 (manufactured by Kuraray Co., Ltd.), Gohsenol GL-05, GH-17, GH-20, and GH-23. (Nippon Synthetic Chemical Industry Co., Ltd.) can be used, but the present invention is not limited by this specific example.

  As the polyvinyl alcohol, modified polyvinyl alcohol having various modifying groups may be used as long as the saponification degree is within the above-mentioned range. Examples of the modifying group include acetoacetyl group, silyl group, quaternary ammonium base, carboxylic acid group, carboxylic acid group, sulfonic acid group, sulfonic acid group, ketone group, mercapto group, amino group, ethylene group, and the like. Can be mentioned. These can be introduced into polyvinyl alcohol by copolymerizing vinyl acetate and the monomer having the modifying group.

  As the polyvinyl alcohol, those having any degree of polymerization can be used, but those having a degree of polymerization in the range of 500 to 4000 are preferably used from the viewpoints of binder strength against silica, quick drying of ink, and the like.

The inkjet acceptor of the present invention can be produced, for example, by mixing an aqueous dispersion of the cationic polyurethane resin (B), silica (C), water-soluble resin (D), and other components as necessary. it can.
As such a production method, for example, the silica (C) and the water-soluble resin (D) previously dispersed or dissolved in an appropriate aqueous medium, and the aqueous dispersion of the cationic polyurethane resin (B) The method of mixing these using various stirrers and dispersers is simple.
It is also possible to produce the cationic polyurethane resin (B), the silica (C), and the water-soluble resin (D) by adding and mixing them in an aqueous medium in any order.
Moreover, it can also manufacture by the method of mixing the aqueous dispersion of the said cationic polyurethane resin (B), the aqueous dispersion of the said silica (C), and the said water-soluble resin (D).

  Examples of the stirrer that can be used in manufacturing the ink jet receiving agent include a stirrer having a turbine blade, a propeller blade, a fiddler blade, a paddle blade, an anchor blade, a max blend blade, a ribbon blade, a disper blade, and the like. it can. Further, as the disperser, for example, various homogenizers, bead mills, sand mills, line mills, colloid mills, and the like can be used.

  As an inkjet receptive agent of this invention, 1-60 mass parts of said water-soluble resins (D) are included with respect to 100 mass parts of said silica (C), and 1-60 mass parts of said cationic polyurethane resins (B) are included. The inclusion is preferred. Moreover, what contains 5-30 mass parts of said water-soluble resins (D) and 1-30 mass parts of said cationic polyurethane resins (B) is more preferable. An ink jet receiving agent having such a blending ratio forms an ink jet receiving layer that has excellent printability with respect to ink, quick drying of ink, and has a desired gloss even when the formed ink jet receiving layer is thinner than the conventional one. Can do.

  The viscosity of the ink jet receiving agent of the present invention is preferably 100,000 mPa · s or less from the viewpoint of storage stability, coating on various substrates, and efficiency of impregnation work.

The ink jet receiving agent of the present invention may contain various additives as necessary within the range not impairing the effects of the present invention.
Examples of the additive include various cross-linking agents such as boric acid, zirconium-based, epoxy-based, isocyanate-based, melamine-based, carbodiimide-based, filler dispersant, colloidal silica, colloidal alumina, inorganic pigment, resin beads, and the like. Anti-blocking agents, ultraviolet absorbers, antioxidants, antistatic agents, antifoaming agents, and nonionic, cationic, anionic, amphoteric hydrocarbons, silicones, fluorines, acetylenic diols Various leveling agents of the system can be used.
The amount of these additives used is not particularly limited as long as the effects of the present invention are not impaired, but is preferably in the range of 0.01 to 30% by mass with respect to the total amount of solids in the inkjet receiver. .

  In addition, the inkjet receiver of the present invention is a known resin that can be dispersed in an aqueous medium within a range not impairing the effects of the present invention, such as vinyl acetate, ethylene vinyl acetate, acrylic, epoxy, and polyester. , Polyamide-based, urethane-based, styrene-butadiene-based, acrylonitrile-butadiene-based, acrylic-butadiene-based synthetic rubber, and the like.

  The above-described additives and the like can be used together when the cationic polyurethane resin (B), the silica (C), and the water-soluble resin (D) are mixed and stirred.

  Next, the ink jet recording medium of the present invention will be described.

  The ink jet recording medium of the present invention is obtained by forming an ink jet receiving layer on a substrate by volatilizing an aqueous medium contained in the ink jet receiving agent after coating or impregnating the ink jet receiving agent on various substrates. In addition, an ink jet recording medium excellent in ink absorbability and water resistance of printed images can be produced.

  Examples of the base material include paper, paperboard, resin-coated paper, various plastic films, synthetic paper, fibers, nonwoven fabrics, spunbond, and woven fabrics and nonwoven fabrics such as artificial leather and natural leather, and / or coating. Can be used.

  As a method for coating or impregnating the ink jet receiving agent on the various substrates, a known and usual method can be used, and is not particularly limited. For example, an air knife coater, a blade coater, a roll coater, a gravure coater, a comma A method using a coating machine such as a coater or a gate roll coater is simple.

  The ink jet receiving agent of the present invention is less susceptible to cracking when coated or impregnated on a substrate. Therefore, when coating or impregnating the inkjet receiving agent on the substrate, a process for preventing cracks on the surface of the inkjet receiving layer to be formed, for example, a drying process or coating under low temperature conditions, is performed a plurality of times. Repeating steps are not necessary.

  The method for volatilizing the aqueous medium after coating the ink jet receiving agent of the present invention on the substrate is not particularly limited, but for example, a method of drying using a dryer is common. The drying temperature may be set to a temperature that can volatilize the aqueous medium and does not adversely affect the substrate.

  The ink jet recording medium of the present invention obtained by the above production method is an ink jet having a thickness in the range of 3 μm to 30 μm in order to maintain the properties such as ink absorbability at a practical level and maintain good production efficiency. Those having a receiving layer are preferable, and the film thickness of 5 to 15 μm, which is 1/3 to 1/2 of the conventional film thickness, is particularly preferable in consideration of ink absorbability, ink quick-drying property, and production cost.

  The ink jet recording medium obtained by the present invention is a photographic ink jet recording medium that is excellent in printability for various inks, quick drying of the ink, exhibits a desired gloss, and provides an ink jet receiving layer that can be realized as a thin film. As particularly useful.

  Hereinafter, the present invention will be described more specifically with reference to examples.

[Synthesis Example 1] Synthesis of Tertiary Amino Group-Containing Polyol (E) -I Into a four-necked flask equipped with a thermometer, a stirring device, a reflux condenser, and a dropping device, polypropylene glycol-diglycidyl ether (epoxy equivalent 201 g / Equivalent.) After charging 590 parts by mass, the flask was purged with nitrogen. Next, after heating using an oil bath until the temperature in the flask reaches 70 ° C., 380 parts by mass of di-n-butylamine is added dropwise over 30 minutes using a dropping device. The reaction was allowed for 10 hours. After completion of the reaction, using an infrared spectrophotometer (FT / IR-460Plus, manufactured by JASCO Corporation), it is confirmed that the absorption peak near 842 cm ⁻¹ due to the epoxy group of the reaction product has disappeared. A tertiary amino group-containing polyol (E) -I (amine equivalent 339 g / equivalent, hydroxyl equivalent 339 g / equivalent) was prepared.

[Synthesis Example 2] Preparation of Cationic Polyurethane Resin Water Dispersion (PUD-I) 588 parts by mass of a polycarbonate polyol (hydroxyl equivalent 986 g / equivalent) obtained by reacting with a polyester (hydroxyl group obtained by reacting neopentyl glycol, 1,4-butanediol, terephthalic acid and adipic acid) Equivalent 951 g / equivalent) was added at 196 parts by mass, and dehydration was performed at 120 to 130 ° C. at a reduced pressure of 0.095 MPa.

  After dehydration, the mixture was cooled to 70 ° C., 529 parts by mass of methyl ethyl ketone was added, and the mixture was sufficiently stirred and mixed while cooling to 50 ° C. After stirring and mixing, 310 parts by mass of 4,4'-dicyclohexylmethane diisocyanate and 0.2 parts by mass of stannous octylate were added and reacted at 70 ° C for 2 hours.

  After completion of the reaction, 140 parts by mass of the tertiary amino group-containing polyol (E) -I obtained in Synthesis Example 1 was added, reacted for 4 hours, cooled to 55 ° C., and 3-aminopropyltriethoxysilane was added. By adding 17 parts by mass and reacting for 1 hour, a urethane prepolymer solution having a terminal isocyanate group was prepared.

  Next, 1125 parts of methyl ethyl ketone and 55 parts by mass of hydroxyethylaminoethylamine were added to the urethane prepolymer solution, and a chain extension reaction was carried out at 55 ° C. for 3 hours.

  Subsequently, 860 parts by mass of methyl ethyl ketone and 49 parts by mass of dimethyl sulfate were added and held at 60 ° C. for 1 hour. . This aqueous dispersion was distilled under reduced pressure to prepare a cationic polyurethane resin aqueous dispersion (PUD-I) having a nonvolatile content of 30% by mass and a pH of 5.9. In addition, pH is the value measured in 25 degreeC environment using the pH meter (Horiba Ltd. make, M-12). Hereinafter, the pH was measured by the same method.

[Synthesis Example 3] Preparation of Cationic Polyurethane Resin Water Dispersion (PUD-II) Same as Synthesis Example 2, except that 10 parts by mass of di-n-butylamine is used instead of 3-aminopropyltriethoxysilane. In this way, a cationic polyurethane resin aqueous dispersion (PUD-II) having a nonvolatile content of 30% by mass and a pH of 5.6 was prepared.

[Synthesis Example 4] Preparation of Cationic Polyurethane Resin Water Dispersion (PUD-III) Changing the amount of 4,4′-dicyclohexylmethane diisocyanate to 357 parts by mass, tertiary amino group-containing polyol (E) -I Instead of using 47 parts by mass of N-methyldiethanolamine and changing the amount of dimethyl sulfate to 47 parts by mass, the nonvolatile content was 22% by mass in the same manner as in Synthesis Example 2. A cationic polyurethane resin aqueous dispersion (PUD-III) having a pH of 6.0 was prepared.

[Example 1]
Dry silica dispersed in the cationic polyurethane resin aqueous dispersion (PUD-I), PVA235 (manufactured by Kuraray Co., Ltd., polyvinyl alcohol having a saponification degree of 88% and a polymerization degree of 3500), and a cationic resin. [A specific surface area of silica: 90 m ² / g, agglomerated particle size: 100 nm] A 12% by mass aqueous dispersion of [Aqueous dispersion (PUD-I): 10% by mass aqueous solution of PVA235: 12% by mass water of dry silica By sufficiently mixing with a stirrer equipped with a propeller blade such that the mass ratio of [dispersion] is 2.3: 15.9: 81.8, an inkjet receptive agent having a non-volatile content of 12% by mass is obtained. Prepared.

  The obtained ink jet receiving agent was coated on an easy-adhesive transparent polyethylene terephthalate film (A-4100, manufactured by Toyobo Co., Ltd.) with an applicator and dried at 50 ° C. for 10 minutes to obtain a thickness. An ink jet recording medium having a 12 μm ink jet receiving layer was prepared.

[Example 2]
The cationic polyurethane resin aqueous dispersion (PUD-II), a 10 mass% aqueous solution of PVA235 [manufactured by Kuraray Co., Ltd., polyvinyl alcohol having a saponification degree of 88 and a polymerization degree of 3500], and dry silica dispersed with a cationic resin [ 12 mass% aqueous dispersion of specific surface area: 90 m ² / g, aggregated particle diameter: 100 nm] [aqueous dispersion (PUD-II): 10 mass% aqueous solution of PVA235: 12 mass% aqueous dispersion of dry silica] Was sufficiently mixed with a stirrer equipped with a propeller blade so that the mass ratio was 2.3: 15.9: 81.8 to prepare an inkjet receiver having a nonvolatile content of 12% by mass.

  The obtained ink jet receiving agent was applied and dried in the same manner as in Example 1 to prepare an ink jet recording medium having an ink jet receiving layer having a thickness of 12 μm.

[Comparative Example 1]
Dry silica dispersed with a cationic resin in which the cationic polyurethane resin aqueous dispersion (PUD-III), PVA235 (manufactured by Kuraray Co., Ltd., polyvinyl alcohol having a saponification degree of 88% and a polymerization degree of 3500) are dispersed with a cationic resin. [Specific surface area: 90 m ² / g, agglomerated particle size: 100 nm] 12 mass% aqueous dispersion [water dispersion (PUD-III): 10 mass% aqueous solution of PVA235: 12 mass% aqueous dispersion of dry silica ] Was mixed sufficiently with a stirrer equipped with a propeller blade so that the mass ratio was 2.3: 15.9: 81.8 to prepare an inkjet receiver having a nonvolatile content of 12% by mass. .

  The obtained ink jet receiving agent was applied in the same manner as in Example 1 to prepare an ink jet recording medium having an ink jet receiving layer having a thickness of 12 μm.

[Comparative Example 2]
10 mass% aqueous solution of PVA235 [manufactured by Kuraray Co., Ltd., polyvinyl alcohol having a saponification degree of 88% and a polymerization degree of 3500] and dry silica dispersed with a cationic resin [specific surface area: 90 m ² / g, aggregated particle diameter: 100 nm] A stirrer equipped with a propeller blade so that the mass ratio of [10 mass% aqueous solution of PVA235: 12 mass% aqueous dispersion of dry silica] was 22.0: 78.0. Was sufficiently mixed to prepare an ink jet receiving agent having a nonvolatile content of 12% by mass.

  The obtained ink jet receiving agent was applied in the same manner as in Example 1 to prepare an ink jet recording medium having an ink jet receiving layer having a thickness of 12 μm.

[Comparative Example 3]
10 mass% aqueous solution of PVA235 [manufactured by Kuraray Co., Ltd., polyvinyl alcohol having a saponification degree of 88% and a polymerization degree of 3500] and dry silica dispersed with a cationic resin [specific surface area: 90 m ² / g, aggregated particle diameter: 100 nm] 12 mass% aqueous dispersion and 5 mass% aqueous solution of zirconium carbonate [mass ratio of 5 mass% aqueous solution of zirconium carbonate: 10 mass% aqueous solution of PVA235: 12 mass% aqueous dispersion of dry silica] 8: 21.1: 76.1, an ink jet receiving agent having a nonvolatile content of 12% by mass was prepared by sufficiently mixing with a stirrer equipped with a propeller blade.

  The obtained ink jet receiving agent was applied in the same manner as in Example 1 to prepare an ink jet recording medium having an ink jet receiving layer having a thickness of 12 μm.

[Comparative Example 4]
A 10% by mass aqueous solution of the cationic polyurethane resin aqueous dispersion (PUD-I) and PVA235 [manufactured by Kuraray Co., Ltd., polyvinyl alcohol having a saponification degree of 88% and a polymerization degree of 3500] was added to an aqueous dispersion (PUD-I). : 10 mass% aqueous solution of PVA235] is sufficiently mixed with a stirrer equipped with a propeller blade so that the mass ratio is 22.0: 78.0, whereby the inkjet receiving agent having a non-volatile content of 12 mass% Was prepared.

  The obtained ink jet receiving agent was applied in the same manner as in Example 1 to prepare an ink jet recording medium having an ink jet receiving layer having a thickness of 12 μm.

[Evaluation method of inkjet recording medium before inkjet printing]
About the surface of the inkjet recording medium obtained in Examples 1-2 and Comparative Examples 1-4, the glossiness and the degree of a crack were evaluated visually.

Evaluation criteria:
<Glossy>
3: Good gloss.
2: The gloss is slightly good.
1: The gloss is poor.

<Crack>
3: There was no crack at all.
2: Some cracks occurred, but no peeling of the receiving layer was observed.
1: Numerous cracks occurred and peeling of the receiving layer was observed.

[Evaluation method for quick drying of ink after printing]
A narrow format ink jet printer (manufactured by Seiko Epson Corporation, PM-950C) was used, and 100% solid images of each color of cyan, magenta, yellow, and black were printed with the dye ink on the ink jet recording medium. Immediately after printing, plain paper was superimposed on the printing portion and lightly pressed, and the amount of ink transferred to the plain paper was visually observed and evaluated according to the following criteria.
Evaluation methods

<Quick-drying>
3: No transfer at all.
2: Slightly transferred.
1: Remarkably transferred.

Claims (7)

An aqueous medium, a cationic polyurethane resin (B) containing a structural unit (A) represented by the following general formula [I] in a molecule dispersed in the aqueous medium, and dry silica (C) dispersed in the aqueous medium And a water-soluble resin (D), and the cationic amino group content in the structural unit (A) in the cationic polyurethane resin (B) is 0.005 to 1.5 equivalents After applying or impregnating a base material with an ink jet receiving agent that is / kg, a microporous type ink jet in which an ink jet receiving layer having a thickness of 5 μm to 15 μm is formed on the base material by volatilizing the aqueous medium. recoding media.

[Wherein, R ₁ represents an alkylene group that may contain an aliphatic cyclic structure, a residue of a dihydric phenol, or a polyoxyalkylene group, and R ₂ and R ₃ independently represent an aliphatic group. An alkyl group which may contain a cyclic structure, R ₄ represents a hydrogen atom or a residue of a quaternizing agent introduced by a quaternization reaction, and X ⁻ represents an anionic counter ion. ] The ink jet recording medium according to claim 1, wherein the cationic polyurethane resin (B) has a structural unit derived from a polyol obtained by esterifying carbonic acid and an aliphatic polyhydric alcohol . The inkjet recording medium according to claim 1, wherein the cationic polyurethane resin (B) has a structural unit derived from an alicyclic polyisocyanate and / or an aliphatic polyisocyanate . The inkjet recording medium according to claim 1, wherein the dry silica (C) is dry silica having a specific surface area of 70 to 100 m ² / g . The inkjet recording medium according to claim 1, wherein the water-soluble resin (D) is polyvinyl alcohol . The inkjet recording medium according to claim 5, wherein the degree of saponification of the polyvinyl alcohol is in the range of 80 mol% to 95 mol% . An aqueous medium, a cationic polyurethane resin (B) containing a structural unit (A) represented by the following general formula [I] in a molecule dispersed in the aqueous medium, and dry silica (C) dispersed in the aqueous medium And a water-soluble resin (D), and the cationic amino group content in the structural unit (A) in the cationic polyurethane resin (B) is 0.005 to 1.5 equivalents After applying or impregnating the substrate with an inkjet receiving agent of / kg, the ink is received on the substrate, and the aqueous medium is volatilized to form an inkjet receiving layer having a thickness of 5 μm to 15 μm on the substrate. A method for producing a porous type ink jet recording medium.

[Wherein, R ₁ represents an alkylene group that may contain an aliphatic cyclic structure, a residue of a dihydric phenol, or a polyoxyalkylene group, and R ₂ and R ₃ independently represent an aliphatic group. An alkyl group which may contain a cyclic structure, R ₄ represents a hydrogen atom or a residue of a quaternizing agent introduced by a quaternization reaction, and X ⁻ represents an anionic counter ion. ]