JP2009046780A - Inkjet-receiving agent for fiber base material, and inkjet recording medium using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet-receiving agent for a fiber base material, enabling an inkjet-receiving layer having extremely superior color development (printability) to be formed in the fiber base material, and to provide an inkjet recording medium. <P>SOLUTION: The inkjet-receiving agent for the fiber base material contains (A) a cationic polyurethane resin containing a structural unit (a) represented by general formula [I] in a molecule, (B) a water-soluble magnesium salt, (C) a cationic group-containing water-soluble resin and an aqueous medium, wherein, the cationic polyurethane resin (A) is dispersed in the aqueous medium, the content of the water-soluble magnesium salt (B) is 10-15 pts.mass based on 100 pts.mass of the solid component in the inkjet receiving agent for the fiber base material. (In the formula, R<SB>1</SB>is an alkylene group which may contain an alicyclic structure, a residue of a dihydric phenol, or a polyoxyalkylene group; R<SB>2</SB>and R<SB>3</SB>are each independently an alkyl group which may contain an alicyclic structure; R<SB>4</SB>is a hydrogen atom or a residue of a quaternarizing agent introduced by a quaternarizing reaction; and X<SP>-</SP>is an anionic counter ion). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an inkjet recording medium that can be used for banners, banners, tapestry, and the like, which can be used for indoor and outdoor advertisements, and an inkjet receiving agent for a textile substrate that can be used for the production thereof.

  In recent years, cumulative progress in ink-jet printing related technology has been remarkable, and it has become possible to obtain an image similar to a silver salt photograph by an ink-jet printer. For this reason, inkjet printers are beginning to be considered for use in the manufacture of advertising signs for indoor and outdoor use as well as home use.

  Among the advertising billboards, the screen printing method, which is known as a method capable of forming a high color image, has been applied to the manufacture of those based on fiber base materials such as banners, banners, and banners. It was. However, since the screen printing method requires a printing plate, it is not a method suitable for small lot production. Moreover, it was not a practically sufficient method in terms of color reproducibility when performing multicolor printing.

  Therefore, it has been specifically studied to apply the ink jet printing technology to the production of the flag, etc., for example, large-format printing called a wide format ink jet printer is possible on the surface of a fiber substrate having a soft texture. A method of printing a desired image or the like using a printer has been studied.

  However, since the surface of the fiber substrate usually has unevenness due to the fiber structure, it may be difficult to form a high-definition image even if printing is performed on the surface. In some cases, the ink adhering to the fiber surface diffuses inside the substrate due to the capillary action of the fiber and it is difficult to form a clear image.

As a method of solving the above problem, a method of laminating an ink jet receiving layer on the surface of a fiber substrate is known. For example, an ink jet recording fabric having an ink absorbing layer on a fiber substrate, the ink absorbing layer Is known to contain fine fibrous cellulose having a diameter of 0.5 μm or less, a water-soluble nonionic polymer, porous silica and a cationic polymer (for example, see Patent Document 1).
However, the fabric still cannot be said to have a practically sufficient level of color developability.

  On the other hand, an aqueous medium, a cationic polyurethane resin containing a structural unit represented by the following general formula [I] in a molecule dispersed in the aqueous medium, polyvinyl alcohol having a saponification degree of 70 to 90 mol%, and water-soluble It is known that an inkjet receiving agent containing a polyvalent metal salt can form a receiving layer excellent in printability for pigment ink, and that the receiving layer can be formed on a fiber substrate (for example, , See Patent Document 2).

〔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. ]

According to the inkjet receiving agent, it is possible to form an ink-jet receiving layer with high color developability (printability) capable of printing a clear image or the like on a fiber substrate.
However, the advertising medium is required to have a very high level of design and high sharpness than before, and the development of an ink jet recording medium that can cope with it is demanded. The recording medium having the receiving layer was not one step beyond the very high level of color developability (printability).

  As described above, although development of an ink jet receiving agent capable of imparting a very high level of excellent color developability to a fiber base is eagerly desired by the industry, such a receiving agent has not been found yet. It was a fact.

JP 11-293571 A JP 2007-168164 A

The problem to be solved by the present invention is to provide an ink jet receiving agent for a fiber base material capable of forming an ink jet receiving layer having a very excellent color developability (printability) with respect to the fiber base material.
Another object of the present invention is to provide an ink jet recording medium having an ink jet receiving layer with excellent color developability.

In general, the present inventors consider that it is important to use a water-soluble magnesium salt that is suitably used for improving ink absorbability and color developability in order to impart excellent color developability to a fiber substrate. We proceeded with the examination. Specifically, a general polyurethane resin, a cationic water-soluble resin, and a water-soluble resin obtained by reacting a urethane prepolymer obtained by reacting polyol and polyisocyanate with a chain extender such as triethanolamine. Inkjet Receiving Agents Containing Soluble Magnesium Salt
However, it has been difficult to form a receiving layer capable of printing an image or the like excellent in color developability or the like as compared with the conventional product.

Therefore, an ink jet receiving agent containing a polyurethane resin having a cationic group in the side chain, a cationic water-soluble resin, and an excess of a water-soluble magnesium salt as described in Document 2 was examined.
According to the above-mentioned receiving agent, it was possible to form an ink jet receiving layer excellent in color developability as compared with the conventional product, but it did not provide such a very high level of color developability as described above.

  As a result of further investigations, the present inventors have found that an inkjet receiver containing a polyurethane resin having a cationic group in the side chain, a cationic water-soluble resin, and a specific amount of a water-soluble magnesium salt is added to the fiber substrate. On the other hand, it has been found that an ink jet receiving layer having remarkably excellent color developability can be formed.

  That is, the present invention relates to a cationic polyurethane resin (A) containing a structural unit (a) represented by the following general formula [I] in the molecule, a water-soluble magnesium salt (B), a cationic group-containing water-soluble resin (C ) And an aqueous medium-containing ink jet receiving agent for a fiber substrate, wherein the cationic polyurethane resin (A) is dispersed in the aqueous medium, and the water-soluble magnesium salt (B) is The present invention relates to an ink jet receiving agent for a fiber substrate, which is contained in an amount of 10 to 15 parts by mass with respect to 100 parts by mass of the solid content of the ink jet receiving agent for a fiber substrate.

〔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. ]

  The present invention also relates to an ink jet recording medium having an ink jet receiving layer formed of the ink jet receiving agent on one side or both sides of a fiber base material.

  According to the ink jet receiving agent for a fiber base material of the present invention, since the surface smoothness is poor as compared with, for example, a plastic film or the like, it is generally difficult to form a clear printed image by the ink jet printing method. Thus, excellent color developability can be imparted. Therefore, the ink jet recording medium having the ink jet receiving layer made of the receiving agent of the present invention can be used for, for example, indoor and outdoor advertising media and decorations, particularly for banners and banners used for advertising purposes.

  The inkjet acceptor of the present invention comprises a cationic polyurethane resin (A) containing a structural unit (a) represented by the following general formula [I] in the molecule, a water-soluble magnesium salt (B), and a water-soluble cationic group. An ink jet receiving agent for a fiber base material comprising a resin (C) and an aqueous medium, wherein the cationic polyurethane resin (A) is dispersed in the aqueous medium, and the water-soluble magnesium salt (B) However, 10-15 mass parts is contained with respect to 100 mass parts of solid content of the said inkjet receptive agent for fiber base materials.

〔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. ]

  First, the aqueous medium constituting the inkjet receiver 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 may be used, or a mixture of water and an organic solvent miscible with water may be used, or only 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 (A) used in the present invention will be described.
The cationic polyurethane resin (A) used in the present invention contains a structural unit (a) represented by the following general formula [I] in the molecule.

[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 in an aqueous medium to the cationic polyurethane resin (A) constituting the present invention. In addition, the structural unit (a) represented by the above general formula [I] is used in combination with a specific amount of a water-soluble magnesium salt (B), which will be described later, to form an ink jet receiving layer having very excellent color developability. Contribute. In addition, the structural unit (a) contributes to the formation of an ink jet receiving layer having improved film-forming properties and glossiness, with improved adhesion of the ink jet ink and water resistance of the printed image.

  The cationic amino group contained in the structural unit (a) represented by the general formula [I] is contained in the cationic polyurethane resin (A) in an amount of 0.005 equivalents / kg to 1.5 equivalents / kg. It is preferable.

  The cationic polyurethane resin (A) 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 (A-3) 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 polyisocyanate (A-4) 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 (A-3) is a precursor for generating a cationic group by neutralizing a tertiary amino group contained in the molecule with an acid or quaternizing with a quaternizing agent. And a compound for imparting water dispersibility to the polyurethane resin.

  The tertiary amino group-containing polyol (A-3) includes, for example, a compound (A-1) having two epoxy groups in one molecule and a secondary amine (A-2) with respect to 1 equivalent of epoxy group. Thus, it is easily obtained by adding 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 (A) can be further improved, R _{1 in the} general formula [II] is a polyoxyalkylene group diglycidyl ether of a polyoxyalkylene glycol, 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, and particularly preferably 300 g / equivalent in that the cationic concentration in the cationic polyurethane resin (A) 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 (A-3) 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 (A-3), or a part or all of the contained tertiary amino group is neutralized with an acid, or a quaternizing agent. In view of the fact that steric hindrance can be reduced when quaternization is carried out, an aliphatic secondary amine having 2 to 18 carbon atoms is preferable, and an aliphatic secondary amine having 3 to 8 carbon atoms is more preferable. .

  A tertiary amino group-containing polyol (A) is obtained by neutralizing part or all of the tertiary amino group of the tertiary amino group-containing polyol (A-3) with an acid or quaternizing with a quaternizing agent. -3) and the polyisocyanate (A-4) can be imparted with water dispersibility to the cationic polyurethane resin (A) obtained.

  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, 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 (A) 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. It is more preferable.

  The reaction method of the compound (A-1) having two epoxy groups in one molecule and the secondary amine (A-2) for obtaining the tertiary amino group-containing polyol (A-3) 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 the reaction control, or for the purpose of reducing the stirring load due to a decrease in viscosity or causing a uniform reaction. .

  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.

  Among the organic solvents described above, when an organic solvent having a low boiling point is used, it is preferable to perform a pressure reaction in a closed system in order to prevent scattering due to volatilization.

  The compound having two epoxy groups in one molecule (A-1) and the secondary amine (A-2) may be supplied together in a reaction vessel and reacted, 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.

  In producing the cationic polyurethane resin (A), in addition to the tertiary amino group-containing polyol (A-3), various polyols (A -5) 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 (A-5), 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, todecanedicarboxylic 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. , Sucrose, 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.

  The ink-jet receiving layer formed by the ink-jet receiving agent of the present invention is required to have long-term storage durability. Therefore, among the polyols (A-5), a highly durable polyol may be used. Polycarbonate polyol is particularly preferable.

  Examples of the polyisocyanate (A-4) that can be used in producing the cationic polyurethane resin (A) of the present invention include aqueous polyisocyanates such as aromatic polyisocyanates, alicyclic polyisocyanates, and aliphatic polyisocyanates. Known and commonly used organic polyisocyanates used in the production of polyurethane resins can be mentioned.

  Examples of the polyisocyanate (A-4) include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, and 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 Socyanate, 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.

  Ink-jet receiving agents are required to improve the water resistance of the receiving layer and the fixing property of the ink-jet ink. However, when the ink-jet recording medium is used as a banner for advertisements used outdoors, the heat-resistant discoloration is particularly important. Improvement in light resistance and light discoloration resistance is required.

  In that case, in order to prevent deterioration of the surface appearance due to thermal discoloration or photodiscoloration, a cationic polyurethane can be obtained by using an alicyclic polyisocyanate and / or an aliphatic polyisocyanate generally called non-yellowing type as the polyisocyanate. It is preferable to introduce a structural unit derived from the alicyclic polyisocyanate and / or aliphatic polyisocyanate according to the resin (A).

  From this point, considering the availability of raw materials, the polyisocyanate (A-4) is 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 4,4′-dicyclohexylmethane diisocyanate. 2,4′-dicyclohexylmethane diisocyanate and 2,2′-dicyclohexylmethane diisocyanate are particularly preferred.

  When the cationic polyurethane resin (A) 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 (A) 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.

  The molecular skeleton of the cationic polyurethane resin (A) is a silane compound exemplified below for the purpose of developing durability by improving the film strength of the ink-jet receiving layer and improving the adhesion to the substrate on which the receiving layer is formed. It may be introduced inside. Exemplary compounds include γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-hydroxylethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropyltriethoxysilane, γ- ( 2-hydroxylethyl) aminopropyltriethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldiethoxysilane, γ- (2-hydroxylethyl) aminopropyl Methyldimethoxysilane, γ- (2-hydroxylethyl) aminopropylmethyldiethoxysilane or γ- (N, N-di-2-hydroxylethyl) aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-amino Propyltriethoxy Orchid, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane or γ- (N-phenyl) aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptophenyltrimethoxysilane, etc. It is done.

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

[Method 1] A polyol (A-5), a polyisocyanate (A-4), and a tertiary amino group-containing polyol (A-3) are charged all at once or separately, and reacted in a solvent or in the absence of a solvent. To produce a polyurethane resin, neutralize some or all of the tertiary amino groups in the resulting polyurethane resin with an acid and / or quaternize with a quaternizing agent, and then add water to disperse the water. How to squeeze.

[Method 2] A polyol (A-5), a polyisocyanate (A-4), and a tertiary amino group-containing polyol (A-3) are charged in one batch or dividedly and reacted in a solvent or in the absence of a solvent. After producing a urethane prepolymer having an isocyanate group at the terminal by the above, 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 added with an acid. A method of quaternizing with a sum and / or quaternizing agent and then adding water to disperse in water.

[Method 3] A polyol (A-5), a polyisocyanate (A-4), and a tertiary amino group-containing polyol (A-3) are charged in one batch or dividedly and reacted in a solvent or without a solvent. To produce a urethane prepolymer having an isocyanate group at the terminal, and neutralize some or all of the tertiary amino groups in the resulting urethane prepolymer with an acid and / or quaternize with a quaternizing agent. A method in which water is added and dispersed in water, and then chain extension is performed using polyamine.

[Method 4] A polyol (A-5), a polyisocyanate (A-4), and a tertiary amino group-containing polyol (A-3) are batched or divided and charged, and reacted in a solvent or under no solvent. To produce a urethane prepolymer having an isocyanate group at the terminal, neutralize part or all of the tertiary amino group with an acid and / or quaternize with a quaternizing agent, and then homogenizer in an aqueous medium. A method of forcibly emulsifying and dispersing in water using a machine such as, followed by chain elongation using polyamine.

[Method 5] A polyol (A-5), a polyisocyanate (A-4), a tertiary amino group-containing polyol (A-3) and a polyamine are charged all at once and reacted in a solvent or under no solvent. To produce a polyurethane resin, neutralize some or all of the tertiary amino groups in the resulting polyurethane resin with an acid and / or quaternize with a quaternizing agent, and then add water to disperse the water. How to squeeze.

  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 (A) aqueous dispersion, From a viewpoint of maintaining the outstanding storage stability of the said cationic polyurethane resin (A) 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. Anionic or amphoteric emulsifiers may be used in combination as long as the mixing stability of the emulsifier to the cationic polyurethane resin (A) aqueous dispersion is maintained.

  When the cationic polyurethane resin (A) 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 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 (A) will be described in detail.

  When the polyol (A-5), the tertiary amino group-containing polyol (A-3) and the polyisocyanate (A-4) are reacted, the equivalent ratio of the isocyanate group and the active hydrogen atom-containing group [(A-4 ) Equivalent of isocyanate group] / [equivalent of hydroxyl group of (A-5) + equivalent of hydroxyl group of (A-3)] is adjusted to a range of 0.9 / 1 to 1.1 / 1. It is preferable.

  When the cationic polyurethane resin (A) 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 (A-4)] / [ The equivalent of hydroxyl group of (A-5) + equivalent of hydroxyl group of (A-3) + equivalent of amino group of polyamine] can be adjusted to a range of 0.9 / 1 to 1.1 / 1. preferable.

  Moreover, you may manufacture the said cationic polyurethane resin (A) 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 the isocyanate group possessed by (A-4)] / [equivalent of the hydroxyl group possessed by (A-5) + the hydroxyl group possessed by (A-3) Equivalent] is preferably adjusted to a range of 1.1 / 1 to 3/1, and more preferably adjusted to a 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.

  Further, the tertiary amino group-containing polyol (A-3) is preferably 0.005 equivalent / kg to 1. wt% with respect to the cationic polyurethane resin (A) in order to exhibit excellent water resistance of the printed image. The range is 5 eq / kg, more preferably 0.03 eq / kg to 1.0 eq / kg, and even more preferably 0.15 eq / kg to 0.5 eq / kg.

  The cationic polyurethane resin (A) 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 (A) 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, the water-soluble magnesium salt (B) used in the present invention will be described.
The water-soluble magnesium salt (B) used in the present invention is a magnesium salt having solubility in water. For example, when a saturated aqueous solution of magnesium salt is prepared using 20 ° C. water, it is contained in 100 g of the saturated aqueous solution. A magnesium salt is 1 g or more.

  It is essential to use the water-soluble magnesium salt (B) in an amount of 10 to 15 parts by mass with respect to 100 parts by mass of the solid content contained in the ink jet receiving agent of the present invention. For example, with an ink jet receiving agent having a water-soluble magnesium salt (B) content of 7 parts by mass, it is difficult to form a receiving layer having a very high level of color developability required by the industry. In addition, even when the content of the water-soluble magnesium salt (B) is 17 parts by mass, it is difficult to form a receiving layer having a very high level of color developability required by the industry. The water-soluble magnesium salt (B) is more preferably used in an amount of 12 to 14 parts by mass with respect to 100 parts by mass of the solid content contained in the ink jet receiving agent of the present invention.

  Further, the excellent color developability of the receiving layer is not achieved only by using the specific amount of the water-soluble magnesium salt (B) as described above, and this is expressed as the cationic polyurethane resin (A). This is the first effect achieved by using the combination. Therefore, in the ink jet receiving agent obtained by combining the specific amount of the water-soluble magnesium salt with the polyurethane resin not used in the structural unit (a), which is conventionally used in the ink jet receiving agent, for example, the effect of the present invention. Can't get.

  As the water-soluble magnesium salt (B), for example, magnesium chloride, magnesium acetate, magnesium nitrate, magnesium sulfate, magnesium chlorate and the like are used from the viewpoint that the effect of improving the absorbability of pigment ink and the effect of post-cure relaxation are high. it can. Only one type of these may be used, or two or more types may be used. Among them, it is particularly preferable to use magnesium chloride and hydrates thereof because of its good solubility in water, low cost and easy availability.

Next, the cationic group-containing water-soluble resin (C) used in the present invention will be described.
The cationic group-containing water-soluble resin (C) refers to a resin having a cationic group among resins that can take a form almost completely dissolved in water. Specifically, for example, amine epichlorohydrin resin, epichlorohydrin polyamide resin, polyethyleneimine salt-containing resin, polyvinylamine salt-containing resin, polyvinylamidine resin, polyallylamine salt-containing resin, polyaminesulfone salt-containing resin, polydiallyldimethylammonium chloride, dicyandiamide- Formalin polycondensate, cation-modified polyvinyl alcohol, cationic group-containing water-soluble acrylic resin, cation-modified starch, neutralized salt of chitosan and the like can be used.
As the cationic group-containing water-soluble resin (C), the use of an amine epihalohydrin resin or epihalohydrin polyamide resin, among others, forms an ink jet receiving layer capable of imparting very good color development to the fiber substrate. This is preferable.

  Moreover, it is preferable to use the said cationic group containing water-soluble resin (C) in the range of 1-25 mass parts with respect to 100 mass parts of solid content contained in an inkjet receiving agent, and 10-15 mass parts. It is more preferable to use in the range. If the ink-jet receiving agent contains the cationic group-containing water-soluble resin (C) within the above range, an ink-jet receiving layer excellent in ink fixation, water resistance, heat discoloration resistance, and light discoloration resistance is formed. Can do.

  As the amine epihalohydrin resin, various resins can be used. For example, a resin having a structure represented by the following general formula (III) can be used. The amine epihalohydrin resin can be obtained, for example, by reacting a secondary amine, epihalohydrin, and other components as necessary.

R ₁ and R ₂ in the general formula (III) each independently represent a hydrogen atom or an alkyl group. X represents a halogen atom. n represents an integer of 1 or more.

  The secondary amine is a compound in which two hydrocarbon groups and hydrogen are bonded to one nitrogen atom, and a compound having a nitrogen atom in the heterocycle and the nitrogen atom having hydrogen.

  As the secondary amine, for example, an aliphatic secondary amine, an aromatic secondary amine, an alicyclic secondary amine, a heterocyclic secondary amine, or the like can be used, and two or more of these may be used in combination. Is possible.

  Specific examples of aliphatic secondary amines include dimethylamine, diethylamine, diisopropylamine, dibutylamine, methylethylamine, methylpropylamine, methylbutylamine, methyloctylamine, methyllaurylamine, and dibenzylamine. Can do.

  Examples of the aromatic secondary amine include N-methylaniline, N-ethylaniline, N-propylaniline, N-butylaniline, N-pentylaniline, N-hexylaniline, N-octylaniline, N-decylaniline, N N-alkylanilines such as laurylaniline and N-benzylaniline, N-methyltoluidine, N-ethyltoluidine, N-propyltoluidine, N-butyltoluidine, N-pentyltoluidine, N-hexyltoluidine, N-octyltoluidine N-alkyltoluidines such as N-decyltoluidine, N-lauryltoluidine, and N-benzyltoluidine, and N-methylnaphthylamine, N-ethylnaphthylamine, N-propylnaphthylamine, N-butylnaphthylamine, N-pentylnaphthy Amine, N- hexyl naphthylamine, N- octyl-naphthylamine, N- decyl naphthylamine, N- lauryl naphthylamines, and N- alkyl naphthylamine such as N- benzyl-naphthyl amine.

  As the alicyclic secondary amine, N-methylcyclohexylamine, N-ethylcyclohexylamine, N-propylcyclohexylamine, N-butylcyclohexylamine, N-hexylcyclohexylamine, N-octylcyclohexylamine, N-decylcyclohexylamine N-alkylcyclohexylamine such as N-laurylcyclohexylamine, N-methylcyclooctylamine, N-ethylcyclooctylamine, N-propylcyclooctylamine, N-butylcyclooctylamine, N-hexylcyclooctylamine, N-alkylcyclooctylamines such as N-octylcyclooctylamine, N-decylcyclooctylamine, and N-laurylcyclooctylamine, and dicyclohexylamine, and Include di cycloalkyl amine di cyclooctyl amine.

  Examples of the heterocyclic secondary amine include piperidine, pyrrolidine, 2-methylpiperidine, and 4-methylpiperidine.

  As the secondary amine, an aliphatic secondary amine is preferable, and among them, dimethylamine and diethylamine are preferable, and dimethylamine is particularly preferable. Furthermore, it is particularly preferable to use dimethylamine alone.

  In addition, as the epihalohydrin, for example, epichlorohydrin, epibromohydrin, methyl epichlorohydrin, methyl epibromohydrin, or the like can be used. Moreover, these can also be used in mixture of 2 or more types. Among these epihalohydrins, it is particularly preferable to use epichlorohydrin from the viewpoint of easy commercial availability and reactivity.

  Further, the amine epihalohydrin resin may be obtained by reacting an amine other than the secondary amine with the secondary amine and the epihalohydrin.

  The amine epihalohydrin resin is, for example, mixed with the secondary amine, the epihalohydrin and, if necessary, other amines other than the secondary amine under stirring under heating conditions, and they are subjected to addition polymerization by a known and conventional method. Can be manufactured.

  The weight average molecular weight of the amine epihalohydrin resin is preferably in the range of 4000 to 10,000 in consideration of miscibility with other blending components, mixing workability, and water resistance of the resulting ink jet receiving layer.

  The epihalohydrin polyamide resin can be obtained by adding an epihalohydrin to a polyamide polyamine obtained by condensing a polyfunctional polyamine such as diethylenetriamine and a polybasic acid such as adipic acid. Specifically, it is preferable to use an epichlorohydrin polyamide obtained by reacting a polyamide polyamine and epichlorohydrin.

  In addition, various water-soluble resins can be used in the ink jet receiving agent of the present invention as necessary.

  Here, the water-soluble resin is a resin that can take a form completely dissolved in water. In the present invention, any structure and manufacturing method can be used. Specific examples thereof include polyvinyl derivatives such as polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl acetal, polyalkylene oxide, starch, methyl cellulose, hydroxy cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, carboxymethyl cellulose, and modified products thereof. Can do.

  Among these, it is preferable to use polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl acetal, polyalkylene oxide, and a cellulose derivative because the ink absorbability of the obtained ink jet receiving layer can be improved.

  Among the above-mentioned, polyvinyl alcohol has physical properties necessary for an ink jet receiving agent such as transparency, film strength, and binder strength against pigments, is easily available, and there are many types including modified products. This is particularly preferable. From these characteristics, it is possible to form an ink jet receiving layer excellent in gloss, transparency, and ink absorbency by using polyvinyl alcohol as a water-soluble resin in the ink jet receiving agent of the present invention.

  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 the polyvinyl alcohol used in the present invention, those having appropriate saponification degree and polymerization degree can be appropriately used according to the required physical properties. In addition, the saponification degree said by this invention represents the ratio of the number of the said hydroxyl group with respect to the total number of the acetic acid group and hydroxyl group which polyvinyl alcohol has as a percentage.

  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 from the viewpoint of improving ink absorbency, color density of printed images, and water resistance. It is preferable to use it.

  In the present invention, it is preferable to use polyvinyl alcohol having a saponification degree in the range of 70 mol% to 90 mol%, and more preferable to use polyvinyl alcohol having a saponification degree in the range of 86 mol% to 89 mol%. . By using polyvinyl alcohol having a saponification degree in such a range, it is possible to suppress a decrease in color developability and a decrease in water resistance of the obtained ink jet receiving layer.

  Specific examples of the polyvinyl alcohol having a saponification degree of 70 mol% to 90 mol% include Kuraray Poval PVA224, PVA235 (manufactured by Kuraray Co., Ltd.), Gohsenol GL-05, GH-17, GH-20, GH- 23 (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) can be used, but the present invention is not limited by this specific example.

  Moreover, as the polyvinyl alcohol, modified polyvinyl alcohol having various modifying groups can be used. 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.

  The polyvinyl alcohol is preferably used in the range of 10 to 60 parts by mass and more preferably in the range of 20 to 40 parts by mass with respect to 100 parts by mass of the solid content contained in the ink jet receiving agent. The ink jet receiving agent having such a blending ratio is excellent in printability and absorptivity for pigment ink, and can form an ink jet receiving layer having good water resistance of a printed image in both pigment ink and dye ink.

  The inkjet acceptor of the present invention includes, for example, a mixture in which a water-soluble resin such as the water-soluble magnesium salt (B) and polyvinyl alcohol is previously dispersed or dissolved in an appropriate aqueous medium, and the cationic polyurethane resin (A). A method of mixing an aqueous dispersion of the above and an aqueous solution of the cationic water-soluble resin (C) using various stirrers and dispersers is simple. Moreover, the aqueous dispersion of the cationic polyurethane resin (A), the aqueous solution of the cationic water-soluble resin (C), the water-soluble magnesium salt (B), the water-soluble resin, and other components are introduced into an aqueous medium. It is also possible to produce by a method of adding and mixing in an arbitrary order.

  Examples of the stirrer that can be used for the production of 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. Examples of the disperser include various homogenizers, bead mills, sand mills, line mills, sonorators, and colloid mills.

  The solid content (nonvolatile content) of the inkjet receiver of the present invention, that is, the mass ratio of the total amount of the cationic polyurethane resin (A), the water-soluble magnesium salt (B), the cationic water-soluble resin (C), and other solids. Is not particularly limited, but needs to be determined in consideration of the viscosity and storage stability of the ink jet receiving agent. In general, when a water-soluble resin is dissolved in an aqueous medium, its viscosity increases exponentially with respect to the concentration of the water-soluble resin. Moreover, storage stability tends to deteriorate as the concentration increases. Therefore, it is preferable to adjust the solid content so that the viscosity of the ink jet receiving agent is 100,000 mPa · s or less, preferably 50,000 mPa · s. It is also necessary to adjust the viscosity so as to be suitable for a coating apparatus or an impregnation processing apparatus used when coating or impregnating various substrates with the ink jet receiving agent of the present invention.

  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 receiving agent of the present invention has different usage methods for applications in which it is desired to maintain gloss and transparency on the surface of the receiving layer and in applications in which it is desired to express concealment, but depending on the purpose and application, In addition, various porous pigments such as clay, alumina, and calcium carbonate may be included. As the porous pigment, it is possible to use silica or alumina that has good ink absorbability, is easily available industrially, and has good compatibility with the cationic polyurethane resin (A) constituting the present invention. Particularly preferred.

  When using the said porous pigment, it is preferable to use in 3 mass%-70 mass% with respect to the total solid in an inkjet receptive agent.

  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.

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

  The ink jet recording medium of the present invention has a receiving layer made of the ink jet receiving agent on one or both sides of a substrate having an uneven surface, specifically, a fiber substrate. The receiving layer may be laminated on the fiber base material, but a part of the receiving layer may be impregnated in the fiber base material.

  The ink jet recording medium of the present invention can exhibit very excellent color developability and water resistance even when ink jet printing is performed with pigment ink, so that it can be used indoors and outdoors such as banners, banners, and tapestry. It can be used for advertising.

  In the ink jet recording medium of the present invention, the ink jet receiving agent is coated on one or both sides of the fiber base material, or impregnated in the fiber base material, and the aqueous medium contained in the ink jet receiving agent is volatilized. Can be manufactured.

  As said fiber base material, the base material which consists of synthetic fibers, such as a polyester fiber, a polyamide fiber, an aramid fiber, natural fibers, such as cotton and hemp, etc. can be used, for example. The fibers may be processed in advance. Moreover, as a form of a base material, the woven fabric (fabric) and nonwoven fabric which consist of an above described fiber are mentioned.

  As a method of coating or impregnating the inkjet receiving agent on the fiber substrate, a known and commonly used method can be used, and is not particularly limited. For example, as a method of coating on one or both sides of the fiber substrate , A gravure method, a coating method, a screen method, a roller method, a rotary method, a spray method, etc., and a method of impregnating the receiving agent into a part or the whole of a fiber substrate, a spray method, Examples include a dipping method for an impregnation bath.

  When the ink jet receiving agent of the present invention is coated on a fiber substrate, it is difficult to cause cracks in the receiving layer to be formed. Therefore, according to the ink jet receiving agent of the present invention, when manufacturing an ink jet recording medium, there is no need for a step for preventing cracking of the receiving layer, for example, a drying process under low temperature conditions or a coating process is repeated several times. It becomes.

  Further, the method of volatilizing the aqueous medium after coating or impregnating the ink jet receiving agent of the present invention on the fiber substrate is not particularly limited, but for example, a method of drying using a dryer. It is common. The drying temperature may be set to a temperature in which the aqueous medium can be volatilized and does not adversely affect the fiber base material.

From the viewpoint of maintaining a very high level of color developability and maintaining good production efficiency, the adhesion amount of the inkjet acceptor on the fiber substrate is 2 to 30% by mass with respect to the weight of the fiber substrate. In view of ink absorbency and production cost, 5 to 20% by mass is particularly preferable.
Further, the color developability of the ink jet recording medium can be further improved by increasing the adhesion amount of the ink jet receiving agent to the fiber base material. However, since the texture of the ink jet recording medium tends to become slightly harder as the adhesion amount increases, it is preferable to adjust appropriately according to the intended use of the recording medium.

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

[Synthesis Example 1] Synthesis of tertiary amino group-containing polyol (E-1) Polypropylene glycol-diglycidyl ether (epoxy equivalent 201 g / p) was added to a four-necked flask equipped with a thermometer, a stirring device, a reflux condenser and a dropping device. 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 (amine equivalent 339 g / equivalent, hydroxyl equivalent 339 g / equivalent) was prepared.

[Synthesis Example 2] Preparation of Cationic Polyurethane Resin Water Dispersion (AI) In a four-necked flask equipped with a thermometer, a stirring device, a reflux condenser and a dropping device, "Nipporan 980R" [Nippon Polyurethane Industry Co., Ltd. Company-made polycarbonate polyol obtained by reacting 1,6-hexanediol and dimethyl carbonate, hydroxyl equivalent 986 g / equivalent. 863 parts by mass were dissolved in 260 parts by mass of methyl ethyl ketone.

  Subsequently, 176 parts by mass of 4,4′-dicyclohexylmethane diisocyanate and 0.2 part by mass of stannous octylate were added and reacted at 75 ° C. for 2 hours, and then the tertiary amino group-containing polyol obtained in Synthesis Example 1 was obtained. 161 parts by mass of (E-1) and 540 parts by mass of methyl ethyl ketone were added and reacted for 15 hours, then cooled to 60 ° C., and further 1.3 parts by mass of methanol was added and reacted for 1 hour.

  Next, 58 parts by mass of dimethylsulfuric acid was added and maintained at 60 ° C. for 3 hours, and then 400 parts by mass of methyl ethyl ketone, 600 parts by mass of isopropanol, and 2942 parts by mass of ion-exchanged water were added and sufficiently stirred to A dispersion was prepared. The aqueous dispersion obtained was distilled under reduced pressure to prepare a cationic polyurethane resin aqueous dispersion (AI) having a nonvolatile content of 40% by mass and a pH of 6.6.

[Example 1]
A 10% by weight aqueous solution of the above-described cationic polyurethane resin aqueous dispersion (AI) and Kuraray Poval PVA235 [manufactured by Kuraray Co., Ltd., saponification degree 87 mol% to 89 mol%, polymerization degree 3500 polyvinyl alcohol], A 53.5 mass% aqueous solution of magnesium chloride hexahydrate and a 52.0 mass% aqueous solution of Kathiomaster PE-30 [manufactured by Yokkaichi Chemical Co., Ltd., dimethylamine / ethylenediamine / epichlorohydrin-based cationic polymer] , [Aqueous dispersion (AI): 10% by mass aqueous solution of Kuraray Poval PVA235: 53.5% by mass aqueous solution of hexahydrate of magnesium chloride: 52.0% by mass aqueous solution of Cathiomaster PE-30] Mix well with a stirrer equipped with a propeller blade so that the ratio is 31.8: 58.9: 5.3: 4.0, After Dilution with water, non-volatile content to prepare a 10 wt% of the fiber substrate for ink-jet receiving agent. The magnesium chloride content was 12 parts by mass with respect to 100 parts by mass of the solid content of the inkjet receiver.

[Example 2]
Instead of the cation master PE-30, a 25% by mass aqueous solution of DK-6830 [manufactured by Seiko PMC Co., Ltd., epichlorohydrin polyamide resin] was used, and [aqueous dispersion (AI): 10% by mass aqueous solution of PVA235: Except that the mass ratio of 53.5 mass% aqueous solution of hexahydrate of magnesium chloride: 25 mass% aqueous solution of DK-6830] was changed to 30.4: 56.4: 5.1: 8.1. An inkjet receiver for a fiber substrate having a nonvolatile content of 10% by mass was prepared in the same manner as in Example 1. The magnesium chloride content was 12 parts by mass with respect to 100 parts by mass of the solid content of the inkjet receiver.

Example 3
The mass ratio of [Aqueous dispersion (AI): PVA235 10 mass% aqueous solution: Magnesium chloride hexahydrate 53.5 mass% aqueous solution: DK-6830 25 mass% aqueous solution] was 30.5. : An inkjet receiver for a fiber substrate having a nonvolatile content of 10% by mass was prepared in the same manner as in Example 2 except that the ratio was changed to 55.2: 6.0: 8.3. The content of magnesium chloride with respect to 100 parts by mass of the solid content of the inkjet receiver was 14 parts by mass.

[Comparative Example 1]
The mass ratio of [Aqueous dispersion (AI): PVA235 10 mass% aqueous solution: Magnesium chloride hexahydrate 53.5 mass% aqueous solution: DK-6830 25 mass% aqueous solution] was 31.7. : 59.1: 0.8: Except for changing to 8.4, an inkjet receiver for a fiber substrate having a nonvolatile content of 10% by mass was prepared in the same manner as in Example 2. The content of magnesium chloride with respect to 100 parts by mass of the solid content of the inkjet receiver was 2 parts by mass.

[Comparative Example 2]
The mass ratio of [Aqueous dispersion (AI): PVA235 10 mass% aqueous solution: Magnesium chloride hexahydrate 53.5 mass% aqueous solution: DK-6830 25 mass% aqueous solution] was 30.9. : 58.5: 2.8: An ink jet receiving agent for a fiber base material having a non-volatile content of 10% by mass was prepared in the same manner as in Example 2 except for changing to 2.8: 7.4. The magnesium chloride content was 7 parts by mass with respect to 100 parts by mass of the solid content of the inkjet receiver.

[Comparative Example 3]
The mass ratio of [Aqueous dispersion (AI): 10% by mass aqueous solution of PVA235: 53.5% by mass aqueous solution of hexahydrate of magnesium chloride: 25% by mass aqueous solution of DK-6830] was 29.6. : 55.6: 7.4: An ink jet receiving agent for a fiber substrate having a non-volatile content of 10% by mass was prepared in the same manner as in Example 2 except that the ratio was changed to 7.4. The content of magnesium chloride with respect to 100 parts by mass of the solid content of the inkjet receiver was 17 parts by mass.

[Method for producing inkjet recording medium]
After impregnating polyester tropical (manufactured by Tanigami Shoten Co., Ltd., polyester fabric) into the ink jet receivers obtained in Examples 1 to 3 and Comparative Examples 1 to 3, nip rolls (roll pressure 3.5 tons, The ink jet recording medium was manufactured by squeezing using a speed of 5 m / min and drying at 120 ° C. for 3 minutes. In addition, the solid content of the inkjet receiver attached to the polyester tropical of any inkjet recording medium was 7.2% by mass with respect to the mass of the polyester tropical.

[Evaluation method of pigment ink printability]
A wide format ink jet printer (manufactured by Seiko Epson Corporation, MAXART PX-7000) is used, and cyan (hereinafter abbreviated as C), magenta (hereinafter abbreviated as M), and yellow are used as the ink jet recording medium. (Hereinafter abbreviated as Y) and black (hereinafter abbreviated as Bk) 100% solid images of each color were printed with pigment ink. The color density of each 100% solid image of C, M, Y, and Bk printed on each ink jet recording medium was measured using a reflection color density meter (D186, manufactured by Gretag). The printability was evaluated by the sum of the color density values of C, M, Y, and Bk. When the color density value is different by about 0.1, it is possible to clearly confirm the difference in sharpness and vividness of the image even by visual observation.

[Evaluation method of pigment ink absorbency]
A wide format inkjet printer, Seiko Epsond Corporation, MAXART PX-7000) was used, and a solid image of Y100% was printed with pigment ink on the inkjet recording medium. Next, a 400% solid image was printed with pigment ink, which was obtained by superimposing 100% of each color of C, M, Y, and Bk on the Y100% solid image. The printed 400% solid image was visually observed and evaluated for bleeding. The presence / absence of bleeding was evaluated as “Yes” when the outline of the 400% solid image was blurred, and as “None” when the outline of the 400% solid image was not blurred.

  In Table 1, “Kuraray Poval PVA235” is a polyvinyl alcohol manufactured by Kuraray Co., Ltd. “DK-6830” is an epichlorohydrin polyamide resin manufactured by Seiko PMC Co., Ltd. Further, “Kachio Master PE-30” is a dimethylamine / ethylenediamine / epichlorohydrin cationic polymer manufactured by Yokkaichi Gosei Co., Ltd.

Claims (7)

Cationic polyurethane resin (A) containing a structural unit (a) represented by the following general formula [I] in the molecule, water-soluble magnesium salt (B), cationic group-containing water-soluble resin (C), and aqueous medium An ink jet receiving agent for a fiber base material, wherein the cationic polyurethane resin (A) is dispersed in the aqueous medium, and the water-soluble magnesium salt (B) is an ink jet ink for the fiber base material. 10 to 15 parts by mass of an ink-jet receiving agent for a fiber substrate, which is contained in an amount of 10 to 15 parts by mass with respect to 100 parts by mass of the solid content of the receiving agent.

[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 receiving agent for a fiber substrate according to claim 1, wherein the water-soluble magnesium salt (B) is magnesium chloride. The inkjet acceptance for fiber base materials of Claim 1 or 2 whose said cationic group containing water-soluble resin (C) is an amine epihalohydrin resin obtained by making a secondary amine and an epihalohydrin react, or an epihalohydrin polyamide resin. Agent. The inkjet receiving agent for a fiber substrate according to claim 3, wherein the secondary amine is dimethylamine and the epihalohydrin is epichlorohydrin. Furthermore, the inkjet receiver for fiber base materials of Claim 1 formed by containing polyvinyl alcohol. An ink jet recording medium having an ink jet receiving layer formed on one side or both sides of a fiber base material using the ink jet receiving agent according to claim 1. The inkjet recording medium according to claim 6, wherein the fiber base material is a fabric.