JP2002059638A - Coating material for ink jet recording paper and ink jet recording paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording paper excellent in coating property, printing property and resistance to water of a printed image. SOLUTION: The coating material for the ink jet recording paper comprises a cationic aqueous polyurethane obtained from a diisocyanate, a triisocyanate, a polyol, a cationic group introducing compound and a polyalkylene glycol monoalkyl ether.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating material for ink jet recording paper containing a cationic aqueous polyurethane having a specific structure and an ink jet recording paper using the coating material. Coating material for ink jet recording paper containing cationic waterborne polyurethane having both nonionic hydrophilic structure and cationic hydrophilic structure, and coatability, printability and water resistance of printed image using the coating material The present invention relates to an ink jet recording paper having excellent properties.

[0002]

2. Description of the Related Art In ink-jet printing, it is known that the surface of paper is coated with a resin in order to improve printability, and various ink-jet recordings coated with aqueous polyurethane are known. Paper has been proposed.

For example, Japanese Patent Application Laid-Open No. 8-118792 proposes to use an aqueous polyurethane having a polyoxyethylene skeleton in the main chain for an ink receiving layer.
Also, JP-A-10-86505, JP-A-11-2
No. 54809, JP-A-11-268406,
Japanese Patent Application Laid-Open No. 2000-153667 discloses that a tertiary amino group having a polyether structure is neutralized with an acid.
The use of cationic aqueous polyurethanes obtained by grading is described. Japanese Patent Application Laid-Open No. 9-221615 proposes using a cationic polymer and an anionic polymer together. Further, Japanese Patent Laid-Open No.
JP-A-5002 proposes to use a nonionic polyurethane resin in combination with a hydrophilic resin.

[0004] However, the conventional inkjet recording paper coated with water-based polyurethane has a problem that the coatability and printability are poor and the water resistance of a printed image is insufficient.

Accordingly, it is an object of the present invention to provide an ink jet recording paper having excellent coating properties, printability and water resistance of a printed image.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of the above-mentioned situation, and as a result, have found that the present invention relates to an ink jet recording paper containing a cationic aqueous polyurethane having a nonionic hydrophilic group in its molecular structure. The inventors have found that the above object can be achieved by using a coating material, and have reached the present invention.

The present invention has been made on the basis of the above findings, and is an ink jet comprising a cationic aqueous polyurethane obtained from diisocyanate, triisocyanate, polyol, polyalkylene glycol monoalkyl ether and a cationic group-introducing compound. An object of the present invention is to provide a coating material for recording paper and an ink jet recording paper using the material.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention having the above-mentioned gist will be described in detail.

In the cationic aqueous polyurethane according to the present invention, examples of the diisocyanate to be used include aliphatic, alicyclic and aromatic polyisocyanates. Specifically, tetramethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, dicyclohexylmethane diisocyanate, 2,4-triisocyanate Range isocyanate, 2,
6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate,
2,2′-diphenylmethane diisocyanate, 3,
3'-dimethyl-4,4'-biphenylene diisocyanate, 1,5-naphthalenediisocyanate, 1,5-
Tetrahydronaphthalenediisocyanate and the like can be mentioned, and each can be used alone or in combination of two or more. Among these diisocyanates, an alicyclic diisocyanate is preferable, and dicyclohexylmethane diisocyanate is more preferable, because the hydrolysis resistance when formed into an aqueous polyurethane is excellent.

In the cationic aqueous polyurethane according to the present invention, the triisocyanate to be used includes, for example, trifunctional isocyanates such as triphenylmethane triisocyanate and 1-methylbenzol-2,4,6-triisocyanate; Carbodiimide trimerization of diisocyanate, isocyanurate trimerization, biuret-modified trimerization, and modified products such as trimethylolpropane adducts, among which isocyanurate trimerization is preferable because the water resistance of the image is good, fat Group isocyanurate trimers are more preferred because they do not color.

If the molar ratio of the above-mentioned diisocyanate and triisocyanate (triisocyanate / diisocyanate) is less than 0.01, it becomes impossible to introduce a required amount of nonionic hydrophilic groups into the polyurethane structure.
In some cases, the effect of improving printability may not be obtained.
If it exceeds 1.0, the water resistance of the image may be degraded. Therefore, 0.01 to 1.0 is preferable, and 0.05 to 0.5 is more preferable.

In the cationic aqueous polyurethane according to the present invention, the polyol used is not particularly limited, and one or more known general polyols can be used in combination. Examples of the polyol include a low molecular polyol, a polyether polyol, a polybutadiene polyol, a silicone polyol, a polyol having an ester bond, and the like.

Examples of the low-molecular polyol include ethylene glycol, 1,2-propanediol,
1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-2, 4-pentanediol,
2,4-pentanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 2,4-diethyl-
1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 3,5-heptanediol, 1,8-octanediol, 2-methyl-1,8
-Octanediol, 1,9-nonanediol, 1,1
Aliphatic diols such as 0-decanediol, diethylene glycol and triethylene glycol, alicyclic diols such as cyclohexanedimethanol and cyclohexanediol, trimethylolethane, trimethylolpropane, hexitols, pentitols, glycerin, pentaerythritol And trihydric or higher alcohols such as tetramethylolpropane.

The polyether polyol includes, for example, ethylene oxide and / or propylene oxide adducts of the above-mentioned low molecular polyol, polytetramethylene glycol, and the like.

Examples of the silicone polyol include silicone oils having a siloxane bond in the molecule and having a hydroxyl group at a terminal.

Examples of the polyol having an ester bond include polyester polyol, polyester polycarbonate polyol, and polycarbonate polyol.

Of these polyols, polyester polyols are preferred because of their good coating properties and printability.

The above polyester polyols include:
A direct esterification reaction between the low molecular weight polyhydric alcohol exemplified above and a polyhydric carboxylic acid or an ester-forming derivative thereof such as an ester, an anhydride or a halide thereof in an amount smaller than the stoichiometric amount of the polyhydric alcohol; Or what is obtained by transesterification is mentioned. Examples of the polycarboxylic acid or an ester-forming derivative thereof include oxalic acid,
Malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, 2-methylsuccinic acid, 2-methyladipic acid,
3-methyladipic acid, 3-methylpentanedioic acid, 2-
Methyloctane diacid, 3,8-dimethyldecane diacid,
Aliphatic dicarboxylic acids such as 3,7-dimethyldecane diacid, hydrogenated dimer acid and dimer acid, aromatic dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid and naphthalenedicarboxylic acid, and alicyclics such as cyclohexane dicarboxylic acid Dicarboxylic acids, trimellitic acid, trimesic acid, polycarboxylic acids such as tricarboxylic acids such as trimers of castor oil fatty acids, acid anhydrides of these polycarboxylic acids, chlorides of the polycarboxylic acids, halides such as bromide, Lower esters such as methyl ester, ethyl ester, propyl ester, isopropyl ester, butyl ester, isobutyl ester and amyl ester of the polycarboxylic acid, γ-caprolactone, δ-caprolactone, ε
-Caprolactone, dimethyl-ε-caprolactone, δ
-Lactones such as valerolactone, γ-valerolactone, and γ-butyrolactone.

In the cationic aqueous polyurethane according to the present invention, as the cationic group-introducing compound, a known general compound capable of introducing a cationic group into the polyurethane structure can be used. Therefore, N, N-dialkylalkanolamines,
N-alkyl-N, N-dialkanolamines and trialkanolamines are preferred, and N-alkyl-N, N-dialkanolamines (hereinafter referred to as N-alkyldialkanolamines) because the amount of cationic groups introduced is easily controlled. Are more preferred. Examples of the N-alkyl dialkanolamine include N-methyldiethanolamine,
N-butyldiethanolamine and the like can be mentioned.

When the above-mentioned N-alkyl dialkanolamines are used, the amount of cationic groups introduced is controlled by the molar ratio of N-alkyl dialkanolamine to polyol (N-alkyl alkanolamine / polyol). When the value is smaller than 0.5, the dispersion stability of the coating material for ink jet recording paper is reduced, and the coating property may be deteriorated. When the value is larger than 20, the water resistance of a printed image is deteriorated. 0.5
To 20 are preferable, and 1.0 to 10 are more preferable.

The polyalkylene glycol monoalkyl ether used in the cationic aqueous polyurethane according to the present invention reacts with an isocyanate group to introduce a nonionic hydrophilic group. It gives a good dispersion state and coatability to the working material. As the polyalkylene glycol monoalkyl ether, the above-mentioned effects are remarkable and, furthermore, ethylene oxide adduct or ethylene oxide / propylene oxide co-adduct of alcohol is preferable because it is inexpensive. Examples of the alcohol constituting the alcohol include methanol, ethanol, propyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl alcohol, secondary butyl alcohol, tertiary butyl alcohol, amyl alcohol, octyl alcohol, lauryl alcohol, and stearyl alcohol. When the molecular weight of these polyalkylene glycol monoalkyl ethers is less than 400, the dispersion stability may be insufficient, and when the molecular weight is more than 4000, the coating properties may be deteriorated.

If the amount of the polyalkylene glycol used is less than 0.01 in terms of the molar ratio of diisocyanate to 1.0, the required amount of nonionic hydrophilic groups cannot be introduced into the polyurethane structure. In some cases, the effect of improving the properties may not be obtained, and if it exceeds 1.0, gelation may occur and coating properties may deteriorate, or the water resistance of the image may deteriorate. Preferably
0.05 to 0.5 is more preferable.

In the cationic aqueous polyurethane according to the present invention, an isocyanate group of diisocyanate and triisocyanate of the above-mentioned raw materials used and a polyol,
Molar ratio of active hydrogen groups of cationic group-introduced compound, polyalkylene glycol monoalkyl ether, and chain extender used as required (isocyanate / active hydrogen)
Is less than 0.5, an excessive amount of polyol or the like remains, and the water resistance of the image may be deteriorated.
If it is larger than this, a large amount of urea bonds will be generated when water is added, and printability and coatability may deteriorate, so 0.5 to 5.0 is preferable, and 1.0 to 3.0 is preferable. Is more preferred.

In the cationic aqueous polyurethane of the present invention, a known method can be used for the production method. For example, for the urethane reaction,
Diisocyanate, triisocyanate, polyol,
A batch reaction method in which a polyalkylene glycol monoalkyl ether and a cationic group-introduced compound are reacted at once may be used, and the following general formula obtained from a triisocyanate and an ethylene oxide adduct of the polyalkylene glycol monoalkyl ether in advance A sequential reaction method in which a nonionic diisocyanate compound represented by (I) is prepared, and then the nonionic diisocyanate compound, diisocyanate, polyol, and a cationic group-introducing compound may be reacted. The latter method is preferred because the composition and physical properties can be easily controlled.

[0025]

Embedded image (Wherein, Y represents a group derived from a triisocyanate, and Z represents a group derived from a polyalkylene glycol monoalkyl ether)

As for the aqueous solution, the above reaction is carried out by
The reaction is performed in a solvent that is inert to the reaction and has a high affinity for water to obtain a prepolymer. Then, the prepolymer is neutralized with a neutralizing agent, and mixed with water and a chain extender used as needed to form a cation. It is preferable to use a prepolymer method for making the aqueous polyurethane.

Solvents which are inert to the reaction used for producing the above cationic aqueous polyurethane and have a high affinity for water include, for example, acetone, methyl ethyl ketone, dioxane, tetrahydrofuran, N-methyl-
2-pyrrolidone and the like can be mentioned. These solvents are usually used in an amount of 3 to 100% by mass based on the total amount of the raw materials used for producing the prepolymer. Of these solvents, those having a boiling point of 100 ° C. or lower are preferably distilled off under reduced pressure after the synthesis of the prepolymer.

If it is necessary to increase the molecular weight of the cationic aqueous polyurethane in the present invention, a well-known general chain extender may be used. Examples of the chain extender include the above-mentioned low molecular weight polyols, ethylenediamine, propylenediamine, hexamethylenediamine, tolylenediamine, xylylenediamine, diaminodiphenylmethane, diaminocyclohexylmethane, piperazine, 2-methylpiperazine, isophoronediamine, melamine And amines such as succinic dihydrazide, adipic dihydrazide, and phthalic dihydrazide. The amount of the chain extender used depends on the molecular weight of the target polyurethane resin, but is usually 0.5 to 10% by mass based on the prepolymer.

As the neutralizing agent used for producing the aqueous urethane, organic carboxylic acids such as formic acid, acetic acid, lactic acid, succinic acid, glutaric acid, and citric acid, and p-toluene sulfone are used for the cationic group. Examples thereof include acids, organic sulfonic acids such as alkyl sulfonates, inorganic acids such as hydrochloric acid, phosphoric acid, nitric acid, and sulfonic acids, epoxy compounds such as epihalohydrin, and quaternizing agents such as dialkyl sulfates and alkyl halides. Usually, the amount of the neutralizing agent used is preferably 0.8 to 1.2 mol, since if the amount is too large or small relative to 1 mol of the cationic group, the printability and the water resistance of the image may be reduced.

The cationic aqueous polyurethane thus obtained is usually adjusted so that the resin solid content is 1 to 90% by mass, more preferably 5 to 80% by mass.

In the coating material for ink jet recording paper of the present invention, a cationic waterborne polyurethane may be used alone, but in order to further improve the balance between printability, water resistance, and coatability. And other water-based resins. For example, various starches, cellulose derivatives such as hydroxyethylcellulose, methylcellulose, carboxymethylcellulose, gelatin, casein, polyvinyl alcohol and its derivatives of various molecular weights and saponification degrees, polyvinylpyrrolidone, styrene-maleic anhydride copolymer, ethylene -Maleic anhydride copolymer, polyacrylamide and derivatives thereof, water-soluble polymers such as polyethylene glycol, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, acrylate-butadiene copolymer, polyvinyl acetate Such as polyurethane, polyacrylate, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate copolymer, ethylene-butadiene-acrylic copolymer, and polyvinylidene chloride. Water dispersible resins such as scan and the like. The amount of the aqueous resin used is appropriately selected according to the purpose of the coating layer to be formed.

The coating material for ink jet recording paper of the present invention may be a material crosslinked with a water-soluble amino resin such as methylated melamine resin, aziridine, epoxy resin, zinc complex or the like. Further, the state of the cationic aqueous polyurethane resin may be an emulsion, a suspension, a colloidal dispersion, an aqueous solution, or the like.

The ink jet recording paper of the present invention is a paper or a plastic sheet as a base material, an ink receiving layer for holding ink on the base material, and a primer provided between the base material and the ink receiving layer. And an overcoat layer provided on the ink receiving layer if necessary. The coating layer made of the above-mentioned coating material for ink jet recording paper may be used as at least one of these layers.

Examples of the paper used as the base include paper obtained from synthetic polymer fiber, synthetic pulp, glass fiber and the like in addition to pulp obtained from natural wood. It is preferable to add a white pigment internally. Examples of the white pigment include silica such as light calcium carbonate such as calcite, colloidal silica, amorphous silica and amorphous silica, calcium bicarbonate, zeolite, kaolin, clay, talc, diatomaceous earth, aluminum hydroxide, and aluminum dioxide. Titanium and organic pigments are exemplified.

In the above-mentioned ink receiving layer, light calcium carbonate such as calcite, colloidal silica,
Silicas such as amorphous silica and amorphous silica, heavy calcium carbonate, zeolite, kaolin, clay, talc, diatomaceous earth, aluminum hydroxide, titanium dioxide, zeolex, zinc oxide, satin white, hydrotalcite, sepiolite, Smectite, magnesium silicate,
You may mix magnesium carbonate, magnesium oxide, an organic pigment, etc. In the ink receiving layer, the cationic aqueous polyurethane according to the present invention and the various water-soluble and water-dispersible polymers described above can be used as a binder for the inorganic pigment and the organic pigment. The amount of the inorganic filler used is usually 5 to 1 based on 100 parts by mass of the binder.
The amount of the organic filler is usually 0.1 to 10 parts by mass with respect to 100 parts by mass of the binder.

The above-mentioned primer layer imparts printability, water resistance of a printed image, prevention of strike-through of ink, and the like to the ink jet recording paper.
It is preferable that a primer layer is provided. The primer layer can be obtained by applying the above-mentioned inorganic pigments and organic pigments as a binder with the above-mentioned aqueous resin such as the cationic aqueous polyurethane or polyvinyl alcohol according to the present invention as a binder.

The above-mentioned overcoat layer comprises the cationic aqueous polyurethane according to the present invention, polyvinyl alcohols, aqueous urethane resin, a polymer resin obtained by polymerizing a monomer having an ethylenically unsaturated bond, and the like. These may be used alone or in combination of two or more.
This is provided when it is necessary to impart gloss, paper feed characteristics, surface damage prevention characteristics, etc. to the ink jet recording paper. Particularly, a polymer composition obtained by polymerizing a monomer having an ethylenically unsaturated bond (hereinafter, referred to as an ethylenic monomer) is suitably used. Examples of such a polymer include methyl acrylate, ethyl acrylate, butyl acrylate, and the like. 2-ethylhexyl acrylate, lauryl acrylate, 2-hydroxyethyl acrylate, acrylates having an alkyl group carbon number of 1 to 18 such as glycidyl acrylate, methyl methacrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate,
Alkyl groups such as 2-hydroxypropyl methacrylate and glycidyl methacrylate having 1 to 18 carbon atoms, methacrylic acid esters, styrene, α-methylstyrene, vinyltoluene, acrylonitrile, vinyl chloride, vinylidene chloride, vinyl acetate, vinyl propionate, acrylamide And a polymer obtained by polymerizing an ethylenic monomer such as N-methylolacrylamide, ethylene, butadiene, acrylic acid, and methacrylic acid. It may be a copolymer using two or more ethylenic monomers in combination, or a substituted derivative of these polymers or copolymers. Further, the overcoat layer may contain the above-mentioned inorganic pigment.

The ink receiving layer, the primer layer and the overcoat layer in the ink jet recording paper of the present invention are usually formed at a coating amount of ¹ to 30 g / m ² .

Further, the ink jet recording paper of the present invention includes, as necessary, a paper strength enhancer, a retention aid, a wet paper strength enhancer, and other additives which are used as needed when making paper as a base material. A dye or the like can be used in combination.

The coating material for ink jet recording paper and the ink jet recording paper of the present invention may contain an ultraviolet absorber and a hindered amine light stabilizer in order to improve weather resistance.

Examples of the ultraviolet absorber include, for example, 2,
4-dihydroxybenzophenone, 2-hydroxy-4
-Methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 5,5'-methylenebis (2-
2-hydroxybenzophenones such as hydroxy-4-methoxybenzophenone); 2- (2′-hydroxy-
5′-methylphenyl) benzotriazole, 2-
(2'-hydroxy-3 ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl)
-5-chlorobenzotriazole, 2- (2'-hydroxy-5'-tert-octylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-dicumylphenyl) benzotriazole, 2,2 '-Methylenebis (4-tert-octyl-6-benzotriazolyl) phenol, 2- (2'-hydroxy-3'-tert-butyl-
2 such as 5'-carboxyphenyl) benzotriazole
-(2'-hydroxyphenyl) benzotriazoles; phenyl salicylate, resorcinol monobenzoate, 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate, 2,4-di-tert. Benzoates such as amylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate, hexadecyl-3,5-di-tert-butyl-4-hydroxybenzoate;
Substituted oxanilides such as 2-ethyl-2'-ethoxyoxanilide and 2-ethoxy-4'-dodecyloxanilide; ethyl-α-cyano-β, β-diphenylacrylate, methyl-2-cyano-3- Cyanoacrylates such as methyl-3- (p-methoxyphenyl) acrylate; 2- (2-hydroxy-4-octoxyphenyl)
-4,6-bis (2,4-di-tert-butylphenyl) -s
-Triazine, 2- (2-hydroxy-4-methoxyphenyl) -4,6-diphenyl-s-triazine, 2-
(2-hydroxy-4-propoxy-5-methylphenyl) -4,6-bis (2,4-di-tert-butylphenyl)
And triaryltriazines such as -s-triazine.

Examples of the hindered amine light stabilizer include 1,6-bis (2,2,6,6-tetramethyl-4-piperidylamino) hexane / dibromoethane polycondensate and 1,6-bis ( 2,2,6,6-tetramethyl-4-piperidylamino) hexane / 2,4-dichloro-6-morpholino-s-triazine polycondensate,
6-bis (2,2,6,6-tetramethyl-4-piperidylamino) hexane / 2,4-dichloro-6-tert-octylamino-s-triazine polycondensate, 1,5,8,
12-tetrakis [2,4-bis (N-butyl-N-
(2,2,6,6-tetramethyl-4-piperidyl) amino) -s-triazin-6-yl] -1,5,8,1
2-tetraazadodecane, 1,5,8,12-tetrakis [2,4-bis (N-butyl-N- (1,2,2,
6,6-pentamethyl-4-piperidyl) amino) -s
-Triazin-6-yl] -1,5,8,12-tetraazadodecane, 1,6,11-tris [2,4-bis (N-butyl-N- (2,2,6,6-tetra Methyl-
4-piperidyl) amino) -s-triazin-6-ylaminoundecane, 1,6,11-tris [2,4-bis (N-butyl-N- (1,2,2,6,6-pentamethyl- 4-piperidyl) amino) -s-triazine-6
Hindered amine compounds such as -ylaminoundecane; among these hindered amine compounds,
2,2,6,6-tetramethyl-4-piperidyl stearate, 1,2,2,6,6-pentamethyl-4-piperidyl stearate, 2,2,6,6-tetramethyl-
4-piperidyl benzoate, bis (2,2,6,6-
Tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, tetrakis (2,2,6,6-tetramethyl-4-piperidyl) butanetetracarboxylate , Tetrakis (1,2,2,6,6-pentamethyl-
4-piperidyl) butanetetracarboxylate, bis (2,2,6,6-tetramethyl-4-piperidyl).
Di (tridecyl) -1,2,3,4-butanetetracarboxylate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) di (tridecyl) -1,2,2
3,4-butanetetracarboxylate, bis (1,
2,2,6,6-pentamethyl-4-piperidyl) -2
-Butyl-2- (3,5-ditert-butyl-4-hydroxybenzyl) malonate, 1- (2-hydroxyethyl) -2,2,6,6-tetramethyl-4-piperidinol / diethyl succinate A compound having an ester bond such as a condensate is preferable because of its excellent compatibility with the urethane resin.

[0043]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Production Examples, Comparative Production Examples, Examples and Comparative Examples. However, the present invention is not limited by the following production examples, comparative production examples, examples and comparative examples.

[Production Example] The cationic water-based polyurethane No. for Examples was prepared according to the following procedures according to the formulations shown in Tables 1 and 2 below. 1 to No. 17 was obtained.

(Procedure) Triisocyanate and polyethylene glycol monomethyl ether were equimolarly charged in a reaction flask and reacted at 90 ° C. for 2 hours under a nitrogen stream to obtain a nonionic diisocyanate compound. A prepolymer solution obtained by adding polyether, diisocyanate, and N-methyldiethanolamine thereto and reacting in an N-methylpyrrolidone solvent at 90 ° C. for 2 hours under a nitrogen stream is mixed with acetic acid having the same mole as N-methyldiethanolamine. Neutralized. The solution is added to a solution having a solid content of 30% by mass.
The solution was added dropwise to an aqueous solution containing 0 ppm of a condensing agent (fluorinated surfactant) to produce a cationic aqueous polyurethane.

The abbreviations in the following table are as follows. (Diisocyanate) HDI; hexamethylene diisocyanate, HMDI; dicyclohexylmethane diisocyanate, CHDI; 1,4-cyclohexylene diisocyanate, IPDI; isophorone diisocyanate (alkylene glycol monoalkyl ether) MPE
G: ethylene glycol monomethyl ether (polyol) 1,6HD; 1,6-hexanediol, NPG: neopentyl glycol, AA: adipic acid, IPA; isophthalic acid, 1,6HD / AA / IP
A: 1,6-hexanediol and adipic acid: isophthalic acid = 1: 1 polyester polyol, NPG / AA
/ IPA: neopentyl glycol and adipic acid: isophthalic acid = 1: 1 polyester polyol, 1,6H
D / AA; polyester polyol of 1,6-hexanediol and adipic acid, NPG / AA /; polyester polyol of 1,6-hexanediol and adipic acid,
PEG; polyethylene glycol

[0047]

[Table 1]

[0048]

[Table 2]

[Comparative Production Examples] The cationic aqueous polyurethane Comparative Examples 1 to 6 for Comparative Examples were obtained according to the following procedures by the formulations shown in Table 3 below. Comparative Examples 1 and 2 correspond to those obtained by removing the nonionic hydrophilic groups from the Production Examples.
Are those using a polyether polyol corresponding to a nonionic hydrophilic group.

(Procedure) Diisocyanate, polyol,
The prepolymer solution obtained by reacting N-methyldiethanolamine in an N-methylpyrrolidone solvent at 90 ° C. for 2 hours under a nitrogen stream was neutralized with acetic acid in the same mole as N-methyldiethanolamine. This solution is solid content 30% by mass.
Was added dropwise to a 550 ppm aqueous solution of a conjugating agent (fluorinated surfactant) so as to obtain cationic aqueous polyurethanes of Comparative Examples 1 to 6.

[0051]

[Table 3]

Example 1 From among the cationic aqueous polyurethanes obtained above, 100 parts by mass of those shown in Table 4, 100 parts by mass of polyvinyl alcohol, and amorphous silica (Mizukasil P, manufactured by Mizusawa Chemical Industry Co., Ltd.) -78
D) After adding 30 parts by mass, dilute with water to adjust the solid content to 10% by mass, and apply it to plain paper so as to have a dry mass of 10 g / m ² to prepare a test paper. An evaluation was performed. Table 4 shows the results.

(Evaluation 1) The coating property was evaluated as follows: も の indicates that the coating property at the time of coating was low and the coating was easy and uniform, and も の indicates that the coating property was high and the coating surface was uneven. Those having high viscosity and extremely difficult to apply were rated as x.

(Evaluation 2) An ink jet printer (MACHJ manufactured by Epson Corporation) was used for the coated test paper.
Using ET MJ-700V2C), three colors of cyan, magenta, and yellow are printed on a stripe pattern having a width of 3 mm, respectively.
The printability of the ink was visually evaluated. The printability is ◎ for those that do not stain at all with a finger immediately after printing, ○ for those that are slightly stained when touched with a finger immediately after printing, but are almost dry,
If it touches with your finger immediately after printing, it will become dirty and the printed surface will not overlap with other printed matter for several minutes until it dries. Those that did not exist were marked as x. The water resistance was evaluated by visually inspecting the printed test paper by dropping one drop of water with a dropper on the boundary between the printed portion and the non-printed portion. ◎ indicates no bleeding, ○ indicates slight bleeding, △ indicates bleeding but a stripe pattern was discernable, and x indicates no bleeding pattern.

[0055]

[Table 4]

Example 2 From among the cationic aqueous polyurethanes obtained above, 100 parts by mass of those shown in Table 5 were added to 50 parts by mass of polyvinyl alcohol, 2 parts by mass of calcium stearate, and amorphous silica (Mizusawa Chemical). 100 parts by mass of Mizukasil P-78D (manufactured by Kogyo Co., Ltd.) were added, diluted with water to adjust the solid content to 7% by mass, and cast on a coated paper so as to have a dry mass of 5 g / m ² .

The coated paper used for the base material was a plain paper made of amorphous silica (Mizukasil P-78 manufactured by Mizusawa Chemical Industry Co., Ltd.).
D) 90 parts by mass, 10 parts by mass of light calcium carbonate, 20 parts by mass of polyvinyl alcohol, 10 parts by mass of a cationic resin (Actex FC-1 manufactured by Morin Chemical Industry Co., Ltd.), and 0.5 parts by mass of sodium polyphosphate. The added undercoating coating liquid was applied so as to be 10 g / m ² .

The obtained test paper was evaluated in the same manner as in Example 1. Table 5 shows the results.

[0059]

[Table 5]

[0060]

According to the present invention, it is possible to provide an ink jet recording paper excellent in coatability, printability, and water resistance of a printed image.

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 2C056 EA13 FC06 2H086 BA01 BA15 BA34 BA37 BA41 4J034 AA04 AA05 BA08 CA04 CB03 CC05 CD01 DA01 DB01 DC02 DC50 DF01 DG02 DG08 HA07 HA08 HA15 HB08 HC03 HC12 HC13 HC17 HC22 HC46 HC52 HC54 HC65 HC67 HC71 JA25 LA32 QB05 RA07 RA09

Claims (6)

[Claims] 1. A coating material for ink jet recording paper comprising a cationic aqueous polyurethane obtained from a diisocyanate, a triisocyanate, a polyol, a cationic group-introducing compound and a polyalkylene glycol monoalkyl ether. 2. The cationic aqueous polyurethane contains a tertiary amino group in the molecule, and a part or all of the cationic group is neutralized with an acid or quaternized with a quaternizing agent. The coating material for ink jet recording paper according to claim 1, which has: 3. A nonionic diisocyanate compound represented by the following general formula (I), wherein said cationic aqueous polyurethane is obtained in advance from a triisocyanate and an ethylene oxide adduct of a polyalkylene glycol monoalkyl ether, is prepared. The coating material for an ink jet recording paper according to claim 1 or 2, which is obtained by reacting the nonionic diisocyanate compound, the diisocyanate, the polyol, and the cationic group-introducing compound. Embedded image (Wherein, Y represents a group derived from a triisocyanate, and Z represents a group derived from a polyalkylene glycol monoalkyl ether) 4. The diisocyanate is an alicyclic diisocyanate, the triisocyanate is an isocyanurate trimer of an aliphatic diisocyanate, the polyol is a polyester polyol, and the polyalkylene glycol monoalkyl ether is a polyethylene glycol monomethyl ether having a molecular weight of 400 to 4,000. 4. The coating material for ink jet recording paper according to claim 1, wherein the cationic group-introducing compound is N-alkyl dialkanolamine. 5. An ink jet recording paper using the coating material for ink jet recording paper according to claim 1. 6. The ink jet recording paper according to claim 5, wherein the substrate has a coating layer comprising a filler and a binder resin.