JP4934780B2 - Aqueous ink-receiving layer forming composition and method for producing the same - Google Patents

Description

  The present invention relates to a composition for forming an aqueous ink receiving layer and a method for producing the same.

For the purpose of improving storage stability, a composition for forming an aqueous ink layer is known in which a boric acid ester and a specific amount of a volatile acid are added to a composition comprising aluminum oxide fine particles and polyvinyl alcohol produced by a gas phase method. (Patent Document 1).
For the same purpose, a composition for forming a water-based ink receiving layer obtained by dispersing aluminum oxide particles using a pressure disperser is known (Patent Document 2).
JP 2006-231595 A JP 2006-327206 A

However, the composition for forming an aqueous ink-receiving layer to which a boric acid ester and a specific amount of volatile acid are added does not provide sufficient storage stability, for example, a significant increase in viscosity within 20 hours at 20 to 30 ° C. There is a problem that gelation occurs.
In addition, the aqueous ink-receiving layer forming composition obtained using a pressure disperser has a problem that sufficient image water resistance cannot be obtained due to poor ink absorbability.
An object of the present invention is to provide a water-based ink-receiving layer forming composition excellent in storage stability and image water resistance.

The water-based ink-receiving layer-forming composition of the present invention is characterized by water dispersion comprising aluminum oxide particles (a), polyvinyl alcohol (b), hydroxycarboxylic acid (c) and water (d) obtained by a gas phase method. Body or
Aluminum oxide particles (a), polyvinyl alcohol (b), hydroxycarboxylic acid (c) and water (d) obtained by the vapor phase method, and inorganic or organic fine particles (e) excluding aluminum oxide (a), polyvinyl Water-soluble polymer (f) excluding alcohol (b), formic acid, acetic acid or inorganic acid (g), antioxidant (h), ultraviolet light inhibitor (i), crosslinking agent (j), dye fixing agent (k) And / or an aqueous dispersion comprising a low boiling point solvent (l),
Based on the weight of the aluminum oxide particles (a), the content of polyvinyl alcohol (b) is 10 to 20% by weight, and the content of hydroxycarboxylic acid (c) is 0.76 to 4.8% by weight. The point is summarized.

In addition, the method for producing the composition for forming an aqueous ink receiving layer of the present invention is a method for producing the above composition for forming an aqueous ink receiving layer, which includes polyvinyl alcohol (b) and hydroxycarboxylic acid (c). And an aqueous solution containing water (d) and a dispersion step of adding the aluminum oxide particles (a) obtained by the gas phase method and dispersing with a triaxial planetary mixer.

  The water-based ink receiving layer forming composition of the present invention is excellent in storage stability and image water resistance. That is, the composition of the present invention can be stored stably for a long period of time without significant thickening or gelation even at 20 to 30 ° C. Further, since the ink absorbability is excellent, it is possible to easily prepare a water-based ink receiving layer having excellent image water resistance.

The aluminum oxide particles (a) obtained by the gas phase method are obtained by a known gas phase method.
As a vapor phase method, (1) a method in which metal aluminum is melted and vaporized in a vacuum vessel and introduced into an oxidizing atmosphere to obtain aluminum oxide particles; (2) metal aluminum powder is used for a flame containing oxygen. A method of obtaining aluminum oxide particles by evaporating and oxidizing them in the inside; and (3) a method of vaporizing aluminum chloride and ejecting it into a burner flame and oxidizing it to obtain aluminum oxide particles (special table 2005-506269, etc.), etc. Is mentioned.

The average primary particle diameter (nm) of the aluminum oxide particles (a) obtained by the vapor phase method is preferably 1 to 50, more preferably 5 to 20, particularly preferably 10 to 15, and most preferably 5 to 20. is there. In this range, the ink absorbability is further improved.
Note that the average primary particle size is in accordance with JIS Z8901-2006 “Testing Powder and Testing Particles” 5.44 Particle Distribution (c) Microscopy, and a sample prepared by a sprinkling method is used with a transmission electron microscope. It is a number average value of equivalent circle diameters calculated by observing 200 or more particles from an image observed by magnifying 50,000 to 1,000,000 times.

The BET specific surface area (m ² / g) of the aluminum oxide particles (a) obtained by the vapor phase method is preferably 50 to 300, more preferably 60 to 200, and particularly preferably 80 to 100. In this range, the ink absorbability is further improved.
The BET specific surface area is measured by a constant volume method using nitrogen adsorption in accordance with JIS R1626-1996 “Method for measuring specific surface area of fine ceramic powder by gas adsorption BET method”.

  The aluminum oxide particles (a) obtained by the vapor phase method can be easily obtained from the market, for example, Aeroxide Alu-c and Al65 manufactured by Degussa; SpctrAl51, 81, 100 manufactured by Cabot, and water thereof. The dispersion CAB-O-SPERSE series is mentioned.

  Examples of the polyvinyl alcohol (b) include fully saponified polyvinyl alcohol (b1), partially saponified polyvinyl alcohol (b2), cation-modified polyvinyl alcohol (b3), anion-modified polyvinyl alcohol (b4), and nonion-modified polyvinyl alcohol (b5). Is included.

The completely saponified polyvinyl alcohol (b1) means polyvinyl alcohol obtained by saponifying polyvinyl acetate in an amount of more than 96 mol% and not more than 100 mol%. On the other hand, partially saponified polyvinyl alcohol (b2) means polyvinyl alcohol obtained by partially saponifying 70 to 96 mol% of the same.
As the fully saponified polyvinyl alcohol and the partially saponified polyvinyl alcohol, known ones (for example, JP-A-2006-28233) can be used.

  As the cation-modified polyvinyl alcohol, known ones (for example, JP-A-10-119423) can be used. The cation-modified polyvinyl alcohol is a polymer having a structure obtained by saponifying, if necessary, a copolymer of an ethylenically unsaturated monomer having a primary to tertiary amino group or a quaternary ammonio group and vinyl acetate. Means.

  As the anion-modified polyvinyl alcohol, known ones (for example, JP-A-1-206088, JP-A-61-237681, JP-A-63-307979 and JP-A-7-285265) can be used. . The anion-modified polyvinyl alcohol means a polymer having a structure obtained by saponifying a copolymer of an ethylenically unsaturated monomer having a carboxy group or a sulfo group and vinyl acetate if necessary.

  As the nonionic modified polyvinyl alcohol, known ones (for example, JP-A-7-9758 and JP-A-8-25795) can be used. The nonionic modified polyvinyl alcohol means a polymer having a structure obtained by saponifying, if necessary, a copolymer of an ethylenically unsaturated monomer having a mercapto group or keto group and vinyl acetate.

As the polyvinyl alcohol (b), partially saponified polyvinyl alcohol and fully saponified polyvinyl alcohol are preferable, and partially saponified polyvinyl alcohol is more preferable.
The saponification degree (mol%) of the partially saponified polyvinyl alcohol is preferably 70 to 96, more preferably 75 to 95, and particularly preferably 85 to 90. Within this range, the image water resistance is further improved.
The degree of saponification is measured according to JIS K6726-1994 “Polyvinyl alcohol test method 3.5 degree of saponification”.

1000-7000 are preferable, as for the average degree of polymerization of polyvinyl alcohol (b), More preferably, it is 2000-6500, Most preferably, it is 3000-6000. Within this range, the image water resistance is further improved.
The average degree of polymerization is measured according to JIS K6726-1994 “Polyvinyl alcohol test method” 3.7 average degree of polymerization. The average degree of polymerization of the cation-modified polyvinyl alcohol is measured by the method described in Japanese Patent No. 3434055.

  Content (weight%) of polyvinyl alcohol (b) is 10-20 based on the weight of the aluminum oxide particle (a) obtained by the gaseous-phase method, Preferably it is 12-19, More preferably, 12. 5 to 18.5, particularly preferably 13 to 18, and most preferably 15 to 17. Within this range, the image water resistance is further improved.

Hydroxycarboxylic acid (c) can be used without limitation as long as it is a compound containing at least one carboxyl group (—COOH) and hydroxyl group (—OH) in one molecule, such as aliphatic oxyacid and aromatic oxyacid. Is included.
Aliphatic oxyacids include glycolic acid, lactic acid, hydroxy (alkyl) acrylic acid esters {hydroxyethyl acrylic acid ester and 4-hydroxybutyl acrylic acid ester}, α-oxybutyric acid, glyceric acid, tartronic acid, malic acid, Examples include tartaric acid and citric acid.
Examples of the aromatic oxyacid include salicylic acid, oxybenzoic acid, gallic acid, mandelic acid, and trovic acid.
Of these, aliphatic oxyacids are preferable, glycolic acid, lactic acid, glyceric acid, malic acid, tartaric acid and citric acid, particularly preferably glycolic acid and lactic acid, and most preferably lactic acid.

  The content (% by weight) of the hydroxycarboxylic acid (c) is 0.76 to 4.8 based on the weight of the aluminum oxide particles (a) obtained by the gas phase method, preferably 0.8 to 3.5, more preferably 0.85 to 3, particularly preferably 0.9 to 2.5, most preferably 1 to 2. Within this range, the storage stability is further improved.

As water (d), tap water, industrial water, distilled water, ion-exchanged water and the like can be used. Of these, distilled water and ion exchange water are preferable from the viewpoint of storage stability, and ion exchange water is more preferable.
The content (% by weight) of water (d) is preferably 40 to 900, more preferably 55 to 570, and particularly preferably 65 to 570, based on the weight of the aluminum oxide particles (a) obtained by the vapor phase method. 400, then preferably 70-355, most preferably 80-300. Within this range, storage stability and image water resistance are further improved.

  The aluminum oxide particles (a), polyvinyl alcohol (b), hydroxycarboxylic acid (c) and water (d) obtained by the gas phase method can be used as one kind or a mixture of two or more kinds, respectively.

  The aqueous ink receptive layer forming composition of the present invention contains other additives {inorganic or organic fine particles excluding aluminum oxide (a) or organic fine particles (e), water-soluble high excluding polyvinyl alcohol (b), if necessary. Molecule (f), organic acid or inorganic acid (g) excluding hydroxycarboxylic acid (c), antioxidant (h), ultraviolet absorber (i), crosslinking agent (j), dye fixing agent (k) and low Boiling point solvent (l) etc.} can be added. Each additive can be used by mixing two or more kinds.

  As inorganic fine particles or organic fine particles (e) excluding aluminum oxide (a), known fine particles (for example, inorganic fine particles described in Japanese Patent Application Laid-Open No. 2005-102467, and organic particles described in Japanese Patent Application Laid-Open No. 2006-192634). Fine particles) can be used. Among these, gas phase method silica fine particles are preferable as the inorganic fine particles, and crosslinked polyvinylpyrrolidone particles are preferable as the organic fine particles.

  As the water-soluble polymer (f) excluding the polyvinyl alcohol (b), a known one (for example, a water-soluble polymer described in JP-A-8-67065) can be used. Of these, polyacrylamide and polyvinylpyrrolidone are preferable from the viewpoint of image water resistance.

  Examples of the organic acid or inorganic acid (g) excluding the hydroxycarboxylic acid (c) include known ones (for example, organic acids and inorganic acids described in JP-A-2001-49158) and their metals (sodium, Potassium, calcium, cesium, zinc, copper, iron, aluminum, zirconium, lanthanum, yttrium, magnesium, strontium, cerium, etc.) salt, ammonium salt or amine (triethylamine, tributylamine, piperazine, 2-methylpiperazine, polyallylamine, etc.) Salt and the like can be used. Among these, from the viewpoint of storage stability, formic acid, acetic acid, hydrochloric acid and nitric acid are preferable, and acetic acid and nitric acid are more preferable.

  As the antioxidant (h), known ones (for example, JP-A-2001-26178) can be used. Among these, a hindered amine antioxidant is preferable from the viewpoint of color developability of a printed image.

  As the ultraviolet absorber (i), known ones {for example, the ultraviolet absorber described in JP-A No. 2000-42614 and the polymer type ultraviolet absorber described in JP-A No. 2004-42614} Etc. can be used. Of these, benzotriazole-based ultraviolet absorbers are preferred from the viewpoint of color development of printed images.

  As the crosslinking agent (j), any compound that can crosslink polyvinyl alcohol (b) can be used without limitation, and known ones (for example, JP 2000-335087 A) can be used. Of these, boron compounds and metal-containing compounds are preferable from the viewpoint of the crosslinking reaction rate, more preferably borax, boric acid, borate, zirconium acetate and zirconium nitrate, and particularly preferably borax, boric acid and zirconium nitrate. .

  As the dye fixing agent (k), known ones (for example, JP-A-10-264511) can be used. Among these, from the viewpoint of color developability of a printed image, an allylamine or a salt polymer thereof, and a diallylalkylamine or a salt polymer thereof are preferable.

  As the low boiling point solvent (l), an organic solvent having a boiling point of 5 to 130 ° C. (preferably 50 to 100 ° C.) can be used. {The number in parentheses is the boiling point. }, Aliphatic alcohol {methanol (65), ethanol (78), isopropanol (82), n-propanol (97), n-butanol (117), etc.}, aliphatic ether {ethyl methyl ether (7), 1, 2-dimethoxyethane (85) etc.}, ketone {acetone (56), methyl ethyl ketone (80), 2-hexanone (127) etc.}, acetate ester {ethyl acetate (77), vinyl acetate (73), isopropyl acetate (90 ), Acetic acid-n-propyl (102), acetic acid-n-butyl (126), etc.}, formic acid ester {ethyl formate (54)}, butyric acid ester {ethyl butyrate (122), vinyl butyrate (116), methyl butyrate ( 103)}, cyclic ether {tetrahydrofuran (66), 1,4-dioxane (101) etc.}, and acetonitrile ( 2), and the like. Of these, aliphatic alcohols are preferable from the viewpoint of image water resistance, more preferably methanol, ethanol and isopropanol, and particularly preferably ethanol and isopropanol.

  When inorganic fine particles or organic fine particles (e) other than aluminum oxide (a) are contained, the content (% by weight) is determined based on the weight of the aluminum oxide particles (a) obtained by the vapor phase method. 1-10 are preferable, More preferably, it is 0.5-5, Most preferably, it is 1-3.

  When the water-soluble polymer (f) excluding the polyvinyl alcohol (b) is contained, the content (% by weight) is 0.01 based on the weight of the aluminum oxide particles (a) obtained by the vapor phase method. ˜2 is preferable, more preferably 0.05 to 1, and particularly preferably 0.1 to 0.5.

  When the organic acid or inorganic acid (g) excluding the hydroxycarboxylic acid (c) is contained, the content (% by weight) is 0 based on the weight of the aluminum oxide particles (a) obtained by the vapor phase method. 0.001 to 3.8 is preferable, 0.004 to 2.4 is more preferable, and 0.76 to 3.2 is particularly preferable.

  When the antioxidant (h) is contained, the content (% by weight) is 0.01 to 20 based on the total weight of the aluminum oxide (a) and the polyvinyl alcohol (b) obtained by the vapor phase method. Is more preferable, 0.05 to 10 is more preferable, and 0.1 to 5 is particularly preferable.

  When the ultraviolet absorber (i) is contained, the content (% by weight) is based on the total weight of aluminum oxide (a), polyvinyl alcohol (b) and hydroxycarboxylic acid (c) obtained by the gas phase method. 0.01 to 20 is preferable, 0.05 to 10 is more preferable, and 0.1 to 5 is particularly preferable.

  When the crosslinking agent (j) is contained, the content (% by weight) is preferably 0.1 to 60, more preferably 0.8 based on the weight of the polyvinyl alcohol (b) obtained by the gas phase method. It is 5-30, Most preferably, it is 1-20.

  When the dye fixing agent (k) is contained, the content (% by weight) is based on the total weight of the aluminum oxide particles (a), the polyvinyl alcohol (b) and the hydroxycarboxylic acid (c) obtained by the gas phase method. Based on this, 0.01 to 10 is preferable, more preferably 0.05 to 5, and particularly preferably 0.1 to 3.

When the low-boiling solvent (l) is contained, the content (% by weight) depends on the aluminum oxide particles (a), polyvinyl alcohol (b), hydroxycarboxylic acid (c) and water (d) obtained by the vapor phase method. ) Is preferably from 0.1 to 50, more preferably from 0.5 to 30, and particularly preferably from 1 to 10.
When these are contained, the storage stability and image water resistance are further improved when the content is in the above range.

The aqueous ink receiving layer forming composition of the present invention can be easily obtained by the following production methods <1> to <5>.
<Method 1> A step of adding and dispersing aluminum oxide particles (a) obtained by a vapor phase method to an aqueous solution containing polyvinyl alcohol (b), hydroxycarboxylic acid (c) and water (d) is included. Production method.
<Method 2> A production method comprising a step of uniformly mixing polyvinyl alcohol (b) and hydroxycarboxylic acid (c) after adding and dispersing aluminum oxide particles (a) obtained by a vapor phase method to water (d). .
<Method 3> After the aluminum oxide particles (a) obtained by the vapor phase method are added to and dispersed in an aqueous solution containing polyvinyl alcohol (b) and water (d), the hydroxycarboxylic acid (c) is uniformly dispersed. A production method including a step of mixing.
<Method 4> After the aluminum oxide particles (a) obtained by the vapor phase method are added to and dispersed in the aqueous solution containing the hydroxycarboxylic acid (c) and water (d), the polyvinyl alcohol (b) is uniformly dispersed. A production method including a step of mixing.
<Method 5> A production method comprising a step of uniformly mixing an aqueous dispersion containing aluminum oxide particles (a) obtained by a vapor phase method, polyvinyl alcohol (b) and hydroxycarboxylic acid (c).
Among these, from the viewpoint of image water resistance, <Method 1> to <Method 4> are preferable, and <Method 1> is more preferable.

  A known disperser (for example, a pressure disperser (such as a high-pressure homogenizer), a ball mill, a sand mill, a roll mill, a planetary mixed disperser, and a three-axis planetary mixer) can be used for dispersion. Among the dispersers, from the viewpoint of storage stability and image water resistance, a planetary disperser and a three-axis planetary mixer are preferable, and a three-axis planetary mixer is more preferable. The three-axis planetary mixer is a disperser having three rotating shafts of two blades that perform planetary motion and a high-speed rotating blade (for example, registered utility model No. 3026043).

  The dispersion temperature is not particularly limited, but is preferably 10 to 50 ° C, more preferably 20 to 45 ° C, and particularly preferably 25 to 35 ° C. Within this range, the storage stability is further improved. The dispersion time is not particularly limited, but is preferably 1 to 48 hours, more preferably 2 to 24 hours, and particularly preferably 5 to 15 hours. Within this range, the image water resistance is further improved.

  Homogeneous mixing can be achieved by known methods. In addition, when mixing polyvinyl alcohol (b) uniformly, after mixing polyvinyl alcohol (b) at 10-25 degreeC, the method of cooling to 80-100 degreeC, stirring, is preferable.

  When other additives are contained, the other additives can be added and mixed in any stage. The water-soluble polymer (f) is preferably mixed with polyvinyl alcohol (b), hydroxycarboxylic acid (c), water (d) and the like. In addition, inorganic fine particles or organic fine particles (e), organic acid or inorganic acid (g), antioxidant (h), ultraviolet absorber (i) and dye fixing agent (k) are oxidized by a vapor phase method. It is preferable to mix uniformly with the aluminum particles (a). Moreover, it is preferable that the low boiling point solvent (l) is finally mixed uniformly. Moreover, it is preferable that the crosslinking agent (j) {particularly the boron compound} is uniformly mixed with the polyvinyl alcohol (b).

  As a support to which the composition for forming a water-based ink receiving layer of the present invention can be applied, paper {paper with sizing, non-size paper, fine paper, medium paper, coated paper, art paper, cast coated paper, paper Resin-coated paper etc. coated on one or both sides with resin (polyolefin, etc.)}, resin film or sheet {polyethylene, polypropylene, polyester, polylactic acid, polystyrene, polyacetate, polyvinyl chloride, cellulose acetate, polyethylene terephthalate, poly Films or sheets made of methyl methacrylate or polycarbonate, etc., and metal-deposited films or sheets thereof, synthetic paper made of films made opaque by filling with inorganic substances or fine foam, etc.}, glass plates, metal plates, cloth, leather, etc. Is mentioned. Among these, it is suitable for a resin film.

  Before applying the aqueous ink receptive layer forming composition of the present invention to a support, an adhesion treatment is performed in advance for the purpose of improving the adhesion between the support and the coating layer on the surface of the support on which the receiving layer is formed. Alternatively, an adhesive treatment may be performed. In particular, when resin-coated paper, resin film, or synthetic paper is used as the support, it is preferable to subject the surface to corona discharge treatment or to provide an undercoat layer made of gelatin, PVA, or the like.

  The aqueous ink receptive layer forming composition of the present invention can be applied using a die coater, roll coater, blade coater, rod coater, bar coater, spin coater or the like.

  After applying the aqueous ink receiving layer forming composition of the present invention, the ink receiving layer is formed by drying the formed coating layer. Drying is preferably performed at 30 to 150 ° C for 0.5 to 15 minutes, more preferably 40 to 80 ° C for 1 to 10 minutes, particularly preferably 45 to 75 ° C for 3 to 8 minutes, most preferably 50 to 50 minutes. 70 ° C., 4-7 minutes.

  The thickness of the ink receiving layer can be appropriately selected depending on the printing method on the coating film, the type of ink used for printing, the type of solvent used in the ink, the amount of ink, and the like, but preferably 1 to 100 μm More preferably, it is 5-70 micrometers, Most preferably, it is 10-50 micrometers, Most preferably, it is 15-45 micrometers.

  The image formation on the ink receiving layer can be performed by various methods such as an ink jet printer, a thermal transfer printer, a laser printer, offset printing, and a writing method using a felt pen.

EXAMPLES Hereinafter, although an Example demonstrates this invention further, this invention is not limited to these Examples at all. Unless otherwise specified, “part” means “part by weight” and “%” means “% by weight”.
<Example 1>
A glass vessel equipped with a stirrer, a thermometer, and a reflux condenser was charged with 216 parts of ion-exchanged water at 15 ° C., and polyvinyl alcohol (b1) {J-POVAL JP-33, manufactured by Nippon Vinegar Bipovar, saponification degree 87 After dispersing 16 parts by mole in a degree of polymerization of 3300} in ion exchange water under an air atmosphere, the temperature was raised to 90 ° C. over 45 minutes under atmospheric pressure (about 1013 hPa), and the mixture was then stirred for 6 hours. An alcohol aqueous solution was prepared.
Subsequently, the aqueous polyvinyl alcohol solution cooled to room temperature (about 23 ° C.) was transferred to a planetary disperser (Planetary Mixer manufactured by Asada Tekko Co., Ltd.), and aluminum oxide particles (a1) {Aeroxide Alu-c, obtained by a vapor phase method, After adding Degussa, primary particle size 13 nm, BET specific surface area 95 m ² / g} 100 parts and hydroxycarboxylic acid (c1) {Tokyo Chemical Industry Co., Ltd., L-lactic acid} 1.5 parts to polyvinyl alcohol aqueous solution, The composition was maintained at 25 to 30 ° C., the output of the stirrer of the disperser was fixed at 80 percent, and stirred and mixed for 1 hour to obtain the aqueous ink receiving layer forming composition (1) of the present invention.

<Example 2>
Aluminum oxide particles (a1) obtained by the vapor phase method were changed to aluminum oxide particles (a2) {SpectrAl81, manufactured by Cabot, primary particle size 14 nm, BET specific surface area 80 m ² / g} obtained by the vapor phase method. Except for this, in the same manner as in Example 1, the aqueous ink-receiving layer-forming composition (2) of the present invention was obtained.

<Example 3>
The aluminum oxide particles (a1) obtained by the vapor phase method are changed to the aluminum oxide particles (a3) {Aeroxide Al65, manufactured by Degussa, primary particle diameter 17 nm, BET specific surface area 65 m ² / g} obtained by the vapor phase method. A water-based ink-receiving layer-forming composition (3) according to the present invention was obtained in the same manner as Example 1 except for the above.

<Example 4>
216 parts of ion-exchanged water was changed to 217 parts, and polyvinyl alcohol (b1) was changed to polyvinyl alcohol (b2) {Kuraray Poval PVA-124, manufactured by Kuraray Co., Ltd., saponification degree 98 to 99 mol%, polymerization degree 2400}. Except having changed, it carried out similarly to Example 1, and obtained the composition (4) for water-based ink receiving layer formation of this invention.

<Example 5>
216 parts of ion-exchanged water was changed to 250 parts, and polyvinyl alcohol (b1) was changed to polyvinyl alcohol (b3) {Kuraray Poval PVA-624, manufactured by Kuraray Co., Ltd., saponification degree 95 mol%, polymerization degree 2400}. Except for this, the aqueous ink-receiving layer-forming composition (5) of the present invention was obtained in the same manner as in Example 1.

<Example 6>
216 parts of ion-exchanged water was changed to 300 parts, and polyvinyl alcohol (b1) was changed to polyvinyl alcohol (b4) {Kuraray Poval PVA-417, manufactured by Kuraray Co., Ltd., saponification degree 80 mol%, polymerization degree 1700}. Except for this, a water-based ink-receiving layer-forming composition (6) of the present invention was obtained in the same manner as in Example 1.

<Example 7>
Example 1 except that 216 parts of ion-exchanged water was changed to 200 parts and that hydroxycarboxylic acid (c1) was changed to hydroxycarboxylic acid (c2) {glycolic acid, manufactured by Tokyo Chemical Industry Co., Ltd., 70% aqueous solution}. In the same manner as above, the aqueous ink-receiving layer-forming composition (7) of the present invention was obtained.

<Example 8>
In the same manner as in Example 1, except that 1.5 parts of hydroxycarboxylic acid (c1) was changed to 0.8 parts of hydroxycarboxylic acid (c3) {Tokyo Chemical Industry Co., Ltd., DL-malic acid}. A composition (8) for forming an aqueous ink receiving layer was obtained.

<Example 9>
Except that 1.5 parts of hydroxycarboxylic acid (c1) was changed to 4.8 parts of hydroxycarboxylic acid (c3), the aqueous ink-receiving layer-forming composition (9) of the present invention was prepared in the same manner as in Example 1. Obtained.

<Example 10>
In the same manner as in Example 1, except that 216 parts of ion-exchanged water was changed to 400 parts, and 1.5 parts of hydroxycarboxylic acid (c1) was changed to 0.77 parts of hydroxycarboxylic acid (c2). An aqueous ink-receiving layer-forming composition (10) of the invention was obtained.

<Example 11>
In the same manner as in Example 1, except that 216 parts of ion-exchanged water was changed to 65 parts, and 1.5 parts of hydroxycarboxylic acid (c1) was changed to 3.5 parts of hydroxycarboxylic acid (c2). An aqueous ink-receiving layer-forming composition (11) of the invention was obtained.

<Example 12>
Except having changed 1.5 parts of hydroxycarboxylic acid (c1) into 0.85 parts, it carried out similarly to Example 1, and obtained the composition (12) for water-based ink receiving layer formation of this invention.

<Example 13>
Except for changing 216 parts of ion-exchanged water to 214 parts and changing 1.5 parts of hydroxycarboxylic acid (c1) to 3 parts, the aqueous ink-receiving layer of the present invention was formed in the same manner as in Example 1. A composition (13) was obtained.

<Example 14>
In the same manner as in Example 1, except that 16 parts of polyvinyl alcohol (b1) were changed to 15 parts and 1.5 parts of hydroxycarboxylic acid (c1) were changed to 0.9 parts. A composition (14) for forming an aqueous ink receiving layer was obtained.

<Example 15>
216 parts of ion-exchange water were changed to 215 parts, 16 parts of polyvinyl alcohol (b1) were changed to 17 parts, and 1.5 parts of hydroxycarboxylic acid (c1) were changed to 2.5 parts Except for this, the aqueous ink-receiving layer-forming composition (15) of the present invention was obtained in the same manner as in Example 1.

<Example 16>
Except that 216 parts of ion-exchanged water was changed to 875 parts and 16 parts of polyvinyl alcohol (b1) were changed to 15 parts, the composition for forming an aqueous ink receiving layer of the present invention was the same as in Example 1. A product (16) was obtained.

<Example 17>
Except having changed 216 parts of ion-exchange water into 70 parts, it carried out similarly to Example 1, and obtained the composition (17) for water-based ink receiving layer formation of this invention.

<Example 18>
Other than changing 216 parts of ion-exchanged water to 565 parts, changing 16 parts of polyvinyl alcohol (b1) to 17 parts, and changing 1.5 parts of hydroxycarboxylic acid (c1) to 1 part In the same manner as in Example 1, the aqueous ink receiving layer forming composition (18) of the present invention was obtained.

<Example 19>
Except having changed 216 parts of ion-exchange water into 41 parts, it carried out similarly to Example 1, and obtained the composition (19) for water-based ink receiving layer formation of this invention.

<Example 20>
Except that 216 parts of ion-exchanged water was changed to 354 parts and 16 parts of polyvinyl alcohol (b1) were changed to 18 parts, the composition for forming an aqueous ink receiving layer of the present invention was the same as in Example 1. A product (20) was obtained.

<Example 21>
216 parts of ion exchange water were changed to 55 parts, 16 parts of polyvinyl alcohol (b1) were changed to 12.6 parts, and 1.5 parts of hydroxycarboxylic acid (c1) were changed to 2 parts. Except for this, a water-based ink-receiving layer-forming composition (21) of the present invention was obtained in the same manner as in Example 1.

<Example 22>
Except that 216 parts of ion-exchanged water was changed to 80 parts and 16 parts of polyvinyl alcohol (b1) were changed to 10 parts, the composition for forming a water-based ink receiving layer of the present invention was the same as in Example 1. A product (22) was obtained.

<Example 23>
Except that 216 parts of ion-exchanged water was changed to 300 parts and 16 parts of polyvinyl alcohol (b1) were changed to 20 parts, the composition for forming a water-based ink receiving layer of the present invention was the same as in Example 1. A product (23) was obtained.

<Example 24>
Except that 216 parts of ion-exchanged water was changed to 157 parts and 16 parts of polyvinyl alcohol (b1) were changed to 12 parts, the composition for forming an aqueous ink receiving layer of the present invention was the same as in Example 1. A product (24) was obtained.

<Example 25>
Except for changing 216 parts of ion-exchanged water to 165 parts and changing 16 parts of polyvinyl alcohol (b1) to 19 parts, the composition for forming an aqueous ink receiving layer of the present invention was the same as in Example 1. A product (25) was obtained.

<Example 26>
Except for changing 216 parts of ion-exchanged water to 171 parts and changing 16 parts of polyvinyl alcohol (b1) to 13 parts, the composition for forming an aqueous ink receiving layer of the present invention was the same as in Example 1. A product (26) was obtained.

<Example 27>
The composition for forming a water-based ink-receiving layer of the present invention was the same as in Example 1, except that 216 parts of ion-exchanged water were changed to 166 parts and 16 parts of polyvinyl alcohol (b1) were changed to 18 parts. A product (27) was obtained.

<Example 28>
Polyvinyl alcohol (b1) was changed to polyvinyl alcohol (b2), 216 parts of ion-exchanged water was changed to 215 parts, and organic acid or inorganic acid (g1) {acetic acid, manufactured by Tokyo Chemical Industry Co., Ltd.} For forming the water-based ink receiving layer of the present invention in the same manner as in Example 1, except that 7 parts were added to the aqueous polyvinyl alcohol solution together with the aluminum oxide particles (a1) and hydroxycarboxylic acid (c1) obtained by the vapor phase method. A composition (28) was obtained.

<Example 29>
Polyvinyl alcohol (b1) was changed to polyvinyl alcohol (b2), 216 parts of ion exchange water was changed to 215 parts, and organic acid or inorganic acid (g2) {Nitric acid, manufactured by Tokyo Chemical Industry Co., Ltd., concentration 60 %} 0.8 part in the same manner as in Example 1 except that 0.8 part was added to the aqueous polyvinyl alcohol solution together with the aluminum oxide particles (a1) and hydroxycarboxylic acid (c1) obtained by the vapor phase method. A composition for forming a receiving layer (29) was obtained.

<Example 30>
That polyvinyl alcohol (b1) was changed to polyvinyl alcohol (b2), 216 parts of ion exchange water was changed to 215 parts, and 0.8 part of organic acid or inorganic acid (g2) and crosslinking agent (j1) { Example 1 except that 0.2 part of triethyl borate, manufactured by Tokyo Chemical Industry Co., Ltd. was added to the polyvinyl alcohol aqueous solution together with aluminum oxide particles (a1) and hydroxycarboxylic acid (c1) obtained by the vapor phase method. Thus, a water-based ink receiving layer forming composition (30) of the present invention was obtained.

<Example 31>
That polyvinyl alcohol (b1) was changed to polyvinyl alcohol (b2), 216 parts of ion-exchanged water was changed to 215 parts, and 0.8 part of organic or inorganic acid (g2) and crosslinking agent (j2) { Zirconium nitrate, manufactured by Daiichi Rare Element Chemical Industries, Ltd., about 55% aqueous solution} 0.3 part was added to the polyvinyl alcohol aqueous solution together with aluminum oxide particles (a1) and hydroxycarboxylic acid (c1) obtained by the vapor phase method. In the same manner as in Example 1, the aqueous ink-receiving layer-forming composition (31) of the present invention was obtained.

<Example 32>
The aqueous ink receptive layer forming composition (1) obtained in Example 1 was redispersed for 3 hours with a planetary disperser (Planetary Mixer, manufactured by Asada Tekko Co., Ltd.), and the aqueous ink receptive layer forming composition of the present invention. (32) was obtained.

<Example 33>
A water-based ink-receiving layer-forming composition (33) of the present invention was obtained in the same manner as in Example 32 except that 3 hours was changed to 5 hours.

<Example 34>
A water-based ink-receiving layer-forming composition (34) of the present invention was obtained in the same manner as in Example 32 except that 3 hours was changed to 10 hours.

<Example 35>
The aqueous ink receptive layer forming composition (1) obtained in Example 1 was redispersed for 1 hour with a triaxial planetary mixer (Asada Iron Works, Planetary Despa, stirrer output 80 percent), and the present invention was made. A water-based ink-receiving layer-forming composition (35) was obtained.

<Example 36>
A water-based ink-receiving layer-forming composition (36) of the present invention was obtained in the same manner as in Example 35 except that 3 hours was changed to 2 hours.

<Example 37>
A water-based ink-receiving layer-forming composition (37) of the present invention was obtained in the same manner as in Example 35 except that 3 hours was changed to 5 hours.

<Example 38>
A water-based ink-receiving layer-forming composition (38) of the present invention was obtained in the same manner as in Example 35 except that 3 hours was changed to 10 hours.

<Comparative Example 1>
While stirring 295 parts of ion-exchanged water, 5 parts of acetic acid and 100 parts of aluminum oxide particles (a1) were added thereto, and the mixture was stirred and dispersed for 2 hours to obtain an aqueous dispersion of alumina.
Next, 20 parts of a 10% aqueous solution of polyvinyl alcohol (b3) and 5.84 parts of triethyl borate were added to and mixed with 400 parts of an aqueous alumina dispersion, and a composition for forming an aqueous ink-receiving layer for comparison (H1). Got. The coating composition gelled after about 30 minutes at about 25 ° C.

<Comparative example 2>
A 30% aqueous dispersion containing 100 parts of aluminum oxide (a1) was applied to a pressure homogenizer (manufactured by Gaurin Co., Ltd., pressure 500 kg / cm ² ) to obtain a fine dispersion.
This fine dispersion and 40 parts of polyvinyl alcohol (b4) were mixed to obtain a comparative water-based ink receiving layer forming composition (H2).

<Comparative Example 3>
Composition for forming an aqueous ink-receiving layer for comparison in the same manner as in Example 1, except that 16 parts of polyvinyl alcohol (b1) was changed to 9 parts and 216 parts of ion-exchanged water were changed to 223 parts. A product (H3) was obtained.

<Comparative example 4>
A comparative water-based ink-receiving layer was formed in the same manner as in Example 1 except that 16 parts of polyvinyl alcohol (b1) were changed to 21.7 parts and 216 parts of ion-exchanged water were changed to 210 parts. A composition (H4) was obtained.

  The aqueous ink-receiving layer forming compositions obtained in the examples and comparative examples were evaluated for storage stability and image water resistance according to the following methods. The results are shown in the following table.

<Storage stability>
An E-type viscometer (Toki Sangyo Co., Ltd.) in which 0.5 ml of a measurement sample {composition for forming a water-based ink receiving layer} after 30 minutes of stirring or mixing or redispersion was adjusted to 25.0 ± 0.5 ° C. RE80L manufactured by company, conical cone with a radius of 7 mm and an angle of 5.24 × 10 ⁻² rad), allowed to stand for 5 minutes, started measurement, and read viscosity (α1) after 3 minutes {JIS Z8803 -1991 "Viscosity of liquids" 9. Cones and Cones-Conforms to viscosity measurement method using a flat plate rotational viscometer. }
On the other hand, the measurement sample was stored hermetically at 25 ± 1 ° C. for 12 hours, and the viscosity (α2) was measured in the same manner as described above.
The ratio (α2 / α1) between (α1) and (α2) was used as an index of storage stability. The closer this ratio is to 1, the smaller the viscosity change and the better the storage stability.

<Image water resistance>
On a polyethylene terephthalate film (A-4100 manufactured by Toyobo Co., Ltd., surface-adhesion-treated), a measurement sample immediately after stirring and mixing or redispersing was dried using a bar coater so that the weight was 20 g / m ² after drying. The coated film was obtained by coating. Subsequently, the coated film was dried in a hot air dryer at 50 ± 3 ° C. for 7 minutes to obtain an ink receiving layer forming film.
Next, a solid ink image was printed on the ink receiving layer forming film using a commercially available inkjet printer (PM800C manufactured by Seiko Epson Corporation), and then the print was adjusted to 23 ± 2 ° C. and 55% RH. It left still in the room for 1 hour, it was made to dry and the printing film was obtained. Subsequently, the printed film is immersed in ion-exchanged water adjusted to 25 ± 2 ° C. for 1 minute, and the color density of the solid image before and after being immersed in the ion-exchanged water is measured using a reflection color density meter (manufactured by Greta Macbeth). did. From these color densities, the color density retention rate (%) was calculated based on the following formula, and this was regarded as image water resistance. The closer the color density retention rate is to 1, the less fading due to immersion in ion-exchanged water and the better the image water resistance.
Color retention (%) = (color density after water immersion) × 100 / (color density before water immersion)

  The aqueous ink receptive layer forming compositions (Examples 1 to 39) of the present invention are far superior in storage stability and image water resistance than the aqueous ink receptive layer forming compositions of Comparative Examples 1 to 4. It was excellent. Among them, the water-based ink-receiving layer forming compositions (Examples 35 to 38) produced using a triaxial planetary disperser were remarkably excellent in storage stability and image water resistance.

  The composition for forming an aqueous ink receiving layer of the present invention is suitable for forming an aqueous ink receiving layer. The composition for forming an aqueous ink-receiving layer of the present invention can be applied to various supports, and printability with aqueous ink can be imparted to the support. Examples of the support include leather, cloth, resin molded body, paper, metal, cardboard, and ceramics. The support to which the composition for forming an aqueous ink receiving layer of the present invention is applied includes a prepaid card, an optical recording medium ( CD-R, CD-RW, DVD, etc.), IC cards, magnetic cards, acrylic resin sheets for electrical equipment, polycarbonate plates for building materials, signboards, display panels, nameplates, nameplates, packaging containers and bags.

Claims (4)

An aqueous dispersion comprising aluminum oxide particles (a), polyvinyl alcohol (b), hydroxycarboxylic acid (c) and water (d) obtained by a vapor phase method, or
Aluminum oxide particles (a), polyvinyl alcohol (b), hydroxycarboxylic acid (c) and water (d) obtained by the vapor phase method, and inorganic or organic fine particles (e) excluding aluminum oxide (a), polyvinyl Water-soluble polymer (f) excluding alcohol (b), formic acid, acetic acid or inorganic acid (g), antioxidant (h), ultraviolet light inhibitor (i), crosslinking agent (j), dye fixing agent (k) And / or an aqueous dispersion comprising a low boiling point solvent (l),
Based on the weight of the aluminum oxide particles (a), the content of polyvinyl alcohol (b) is 10 to 20% by weight, and the content of hydroxycarboxylic acid (c) is 0.76 to 4.8% by weight. A composition for forming a water-based ink-receiving layer. The composition according to claim 1, wherein the hydroxycarboxylic acid (c) is at least one selected from the group consisting of glycolic acid, lactic acid, glyceric acid, malic acid, tartaric acid and citric acid. A method for producing the water-based ink-receiving layer forming composition according to claim 1, comprising:
Dispersion in which aluminum oxide particles (a) obtained by a vapor phase method are added to an aqueous solution containing polyvinyl alcohol (b), hydroxycarboxylic acid (c) and water (d), and dispersed by a triaxial planetary mixer A process for producing a composition for forming an aqueous ink-receiving layer, which comprises a step. A method for producing an ink receiving layer, comprising: applying the aqueous ink receiving layer forming composition according to claim 1 or 2 to a support; and drying the formed coating layer.