JPH11240242A - Inkjet recording sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-quality image by using an aqueous inkjet printer, and to provide water resistance and ink fixation even on paper provided with an ink receiving layer mainly composed of an inexpensive pigment. Provided is an ink-jet recording sheet having high image quality and capable of obtaining a high-definition image having a high image density. An ink jet recording sheet provided with an ink receiving layer on a support, wherein the ink receiving layer mainly comprises aluminosilicate fine particles, a pigment, a binder,
The aluminosilicate fine particles are cationic and have an average particle size of 5 nm to 1 μm and a content of 0.5% by weight to 20%.
A method for producing an ink jet recording sheet in which the weight is%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording sheet used for various printers such as a personal computer, and more particularly to an ink jet recording sheet excellent in water resistance and ink fixing property.

[0002]

2. Description of the Related Art The ink jet recording method is a method in which small droplets of ink are caused to fly from nozzles by various methods, and recording is performed by adhering and absorbing ink droplets on an ink jet recording sheet. This method has features such as low noise, high-speed recording, and compatibility with colorization. In recent years, with the advancement of the performance of personal computers and the spread of multimedia, there has been an increasing demand for printing and outputting documents including color and color images at offices and homes, and the inkjet recording method is an optimal recording method for such purposes. It has been considered that an ink jet recording sheet corresponding to this method and suitable for color print output is desired.

A conventional ink jet recording sheet is usually an ink jet recording sheet obtained by applying a paint obtained by mixing a pigment such as finely divided silica or calcium carbonate with polyvinyl alcohol or a water-soluble resin on the surface of pulp paper. Had been used. Japanese Patent Application Laid-Open No. Sho 62-15084 discloses an ink jet recording medium having at least one or more ink receiving layers mainly composed of synthetic fine particle silica on a support.

However, since the dyes generally used in the ink jet recording system are anionic acid dyes or direct dyes, it is difficult for the ink dyes to be fixed in an ink receiving layer mainly containing anionic silica, and an image is formed by water droplets or the like. There were problems such as bleeding and the inability to obtain a high-definition image.

Japanese Patent Application Laid-Open No. 60-219084 is characterized in that, in a recording medium having at least one ink receiving layer provided on a support, cationic colloidal silica is contained in the ink receiving layer. An ink jet recording medium is disclosed. However, the cationic colloidal silica used here is obtained by forming a cationic metal film such as aluminum on the surface of colloidal silica particles composed of silicon and oxygen and performing a cation treatment. Therefore, subsequent to the production process of colloidal silica, it is necessary to separately perform a cationization treatment,
There is a problem in terms of productivity or cost for industrial use.

[0006]

SUMMARY OF THE INVENTION The present invention provides a high-quality image using a water-based ink jet printer, and provides a water-resistant ink-jet printing method even on paper provided with an ink-receiving layer mainly composed of inexpensive pigments. It is an object of the present invention to provide an ink jet recording sheet having a high image quality and an ink fixing property and capable of obtaining a high definition image with a high image density.

[0007]

In order to solve the above problems, the present invention employs the following constitution. That is, the first invention of the present invention relates to an ink jet recording sheet provided with an ink receiving layer containing aluminosilicate fine particles, a pigment, and a binder on a support, wherein the aluminosilicate fine particles are cationic, and 0.5% by weight to 20%
% Of an ink jet recording sheet ". According to a second aspect of the present invention, there is provided a method according to the first aspect, wherein the aluminosilicate fine particles have an average particle size of 5
nm to 1 μm ”.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The aluminosilicate fine particles used in the present invention are obtained by a mixed hydrolysis method of a silicate alkoxide and an aluminum alkoxide. A method for producing such aluminosilicate fine particles is disclosed in No. 9-234948.
That is, it is produced by dispersing a silicic acid alkoxide and an aluminum alkoxide in an organic solvent, and performing mixed hydrolysis in the presence of water and, if necessary, an acid catalyst.

As a mixed hydrolysis method, for example, a method in which a dispersion in which an aluminum alkoxide is dispersed in an organic solvent together with an acid catalyst and a dispersion in which a silicate alkoxide and an acid catalyst are dispersed in water are mixed and hydrolyzed. Alternatively, a dispersion obtained by dispersing aluminum alkoxide in an organic solvent together with an acid catalyst and a dispersion obtained by partially hydrolyzing silicate alkoxide and water in an organic solvent together with an acid catalyst are mixed. A method in which water containing a catalyst is added and mixed and hydrolyzed is exemplified.

The ratio of the alumina component (Al ₂ O ₃ ) to the silica component (SiO ₂ ) in the aluminosilicate fine particles can be arbitrarily controlled by adjusting the compounding ratio of the alkoxide. Use those that show cationicity. The term "cationic" as used herein means that the zeta potential of the fine particles is positive when measured in water. The zeta potential of the aluminosilicate fine particles used in the present invention is preferably from +5 mV to +70 m
V, more preferably +10 mV to +60 mV. The ratio of the alumina component and the silica component of the aluminosilicate fine particles exhibiting cationicity in water varies depending on the production method, but is approximately 99.9:
The range is from 0.1 to 30:70.

The average particle size of the aluminosilicate fine particles is preferably from 5 nm to 1 μm. Here, the average particle size is a value measured by a laser particle size meter based on the photon correlation method. If the average particle size is less than 5 nm, the sol containing the aluminosilicate fine particles is mixed with a binder, and the viscosity may be increased when a coating material is prepared, which is not preferable. On the other hand, if the average particle size exceeds 1 μm, the fixing ability of the ink becomes small, and the water resistance tends to be inferior.

The ink receiving layer of the present invention contains at least aluminosilicate fine particles, a binder and a pigment. The compounding amount of the aluminosilicate fine particles is preferably 0.5% by weight to 20% by weight of the total solids of the receiving layer in terms of dry weight. If the amount is less than 0.5% by weight, the effect of fixing the ink dye by the aluminosilicate fine particles is not sufficient, and if the amount is more than 20% by weight, the ink dye fixing property is hardly improved, which is economically disadvantageous. In this case, the ink absorption speed is slow, and the image quality is sometimes deteriorated. A more preferred range is from 5% to 15% by weight.

The pigments contained in the ink receiving layer include colloidal silica, cationic colloidal silica, alumina sol, pseudoboehmite, amorphous silica, kaolin, titanium oxide, clay, calcined clay, talc, zinc oxide, tin oxide, magnesium sulfate, Aluminum oxide, aluminum hydroxide, satin white, aluminum silicate, smectite, zeolite, magnesium silicate, magnesium carbonate, magnesium oxide, diatomaceous earth, styrene plastic pigment Heavy calcium carbonate, light calcium carbonate, etc., as well as urea-resin plastic pigment And benzoguanine-based plastic pigments. The compounding amount of such a pigment is desirably 40 to 90% by weight of the total solids of the receiving layer on a dry weight basis. If it is less than 40% by weight, the ink absorbency becomes insufficient, and if it exceeds 90% by weight, the layer strength may be reduced.

Examples of the binder to be incorporated in the ink receiving layer include completely saponified polyvinyl alcohol, incompletely saponified polyvinyl alcohol, cationized polyvinyl alcohol, silicon-containing polyvinyl alcohol, polyvinylpyrrolidone, casein, soybean casein, modified soybean casein,
Water-soluble resins such as synthetic proteins, gelatin, starch, cationized starch, phosphated starch, modified starch, diene-based latex of styrene-butadiene copolymer, acrylic polymer latex, and ethylene-vinyl acetate copolymer And latexes such as a vinyl polymer latex. Above all, high polymerization degree completely saponified PVA having a polymerization degree of 2000 to 4000
Is preferred from the viewpoint of the water resistance of the coating film. The binder is selected from the range of 10 to 59.5% by weight in the ink receiving layer, and preferably 15 to 40% by weight.

As the substrate sheet, any of plastic film, pulp paper and synthetic paper can be used. For example, examples of the plastic film include films of polyethylene terephthalate, polyvinyl chloride, polycarbonate, polyimide, cellulose triacetate, cellulose diacetate, polyethylene, and polypropylene.

Examples of the pulp paper include high quality paper, medium quality paper, coated paper, art paper, cast coated paper, paperboard, synthetic resin laminated paper, and metallized paper.

The thickness of the support is determined by the final use of the ink jet recording paper, but is 15 to 200 μm, and the basis weight is 2
0 to 200 g / m ² is preferably used. The ink receiving layer of the present invention is a blade coater, an air knife coater,
Coating can be performed using a known method such as a roll coater, a bar coater, a gravure coater, a rod blade coater, a lip coater, and a curtain coater. Range as a solid content of 3g / m ² ~100g / m ² as coated amount is useful. When the coating amount is small, the ink absorbency is insufficient, and the image may be deteriorated. On the other hand, when the coating amount exceeds 100 g / m ² , cracks are easily generated in the coating film, and the coating becomes difficult and costs are unnecessarily increased. A more preferred range is 10
a ^{g / m 2 ~50g / m 2} .

In the following, the present invention will be described in more detail with reference to Examples, but the method of measuring test items described in Examples and Comparative Examples is as follows. <Method of Measuring Particle Size of Fine Particles> The particle size was measured with a laser particle size distribution meter (trade name: LPA3100, manufactured by Otsuka Electronics Co., Ltd.).
The measurement principle is based on the laser method. This measurement shows that He-Ne
The light scattering method is based on the principle that laser light is irradiated, light is scattered by Rayleigh scattering, and Doppler shift is caused by movement of particles.

<Method of Measuring Zeta Potential of Fine Particles> The zeta potential was measured by a zeta potential meter (Zeta Sizer 2000, trade name, manufactured by Siber Hengner Japan Ltd.). This measurement is performed by moving charged particles dispersed in a liquid by applying an electric field to the entire system, and measuring the mobility.

<Measurement method of pulp beating degree> The measurement of pulp beating degree was based on the method described in TAPPI Standard T200 "Processing method of pulp in a laboratory, beater method" and T227 "Freeness of pulp".

<Stigecht sizing degree> The stiffig sizing degree was measured by a method according to JIS P-8122 "Testing method for the Stigecht sizing degree of paper".

<Recording Characteristics> The ink jet recording paper was printed with a color ink jet printer (trade name: PM700C, manufactured by Seiko Epson Corporation, paper mode for fine use) and evaluated. Uniform printing was observed and evaluated in the state of density unevenness when solid printing was performed. The ink absorbency was evaluated by observing the degree of ink bleeding. The water resistance was immersed in still water for 1 minute, and the state of dye elution was observed and evaluated.
Evaluation of print uniformity, ink absorptivity, and water resistance are shown as ◎, particularly excellent in performance, ○ for excellent, △ for normal quality, and × for defective in use. .

[0023]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should be understood that the present invention is by no means restricted thereto.

<Example 1> A glass reaction vessel having a capacity of 5 liters (with a separable flask, a stirring blade and a thermometer)
131.6 g of aluminum isopropoxide (0.6 g)
1 mol, manufactured by Wako Pure Chemical Industries, purity 95%) and 1.25 kg (20.8 mol) of isopropanol were added, and the temperature was increased to 70 ° C.
The temperature was raised to dissolve the aluminum isopropoxide. Separately, 47.3 g of silicon tetraethoxide (0.216 mol, manufactured by Wako Pure Chemical Industries, purity: 95%) and 38.88 g of isopropanol were placed in a 200 cc eggplant flask.
(0.65 mol) and 7.78 g (0.432 mol) of water were charged and reacted at 85 ° C. for 6 hours. After that, it was added to the above aluminum isopropoxide solution and mixed well. Thereafter, 446 g (24.8 mol) of distilled water was added to the mixture.
In addition, at the same time, 8.23 g of nitric acid (65% solution, 0.085 g)
Mol) was added to carry out a mixed hydrolysis reaction at 85 ° C. 1
After reacting for 2 hours, the obtained reaction liquid was concentrated to remove isopropanol, and a white sol of aluminosilicate fine particles having a solid content of 15% was obtained. The obtained sol was charged in an autoclave made and heat-treated at 160 ° C. for 2 hours. The dried product (dried at 100 ° C.) of the obtained sol had an amorphous structure by powder X-ray diffraction. When the average particle size was measured with a laser particle size distribution meter, it was 10 nm.
Met. When the zeta potential was measured, it was +55 mV.
Met.

Next, a coating composed of 60 parts of finely divided silica (trade name: Fine Seal X60, manufactured by Tokuyama Corporation), 20 parts of polyvinyl alcohol (trade name: PVA124, manufactured by Kuraray), 5 parts of aluminosilicate fine particles obtained by the above-described manufacturing process, and 250 parts of water 1 was prepared. Separately, 20 parts of light calcium carbonate was beaten to a freeness of 400 ml and added to a suspension of 100 parts of bleached hardwood kraft pulp (whiteness: 91%) in water, 1 part of cationic starch, alkenyl succinic anhydride-based neutralizing agent 0.05 parts were added to obtain a papermaking raw material. 64 g / m ² using a fourdrinier multi-cylinder paper machine in a conventional manner.
Quality paper was manufactured. The whiteness was 92%, the calcium carbonate content was 15.0%, the Stöckigt sizing degree was 5 seconds, and the pH of the paper was 6.5. The paint 1 was applied to the surface of the paper using a bar coater so as to have a dry weight of 10 g / m ² and dried to prepare an ink jet recording sheet having an ink receiving layer.

<Example 2> The procedure of Example 1 was repeated except that the amount of nitric acid in Example 1 was changed to 1.03 g (65% concentration solution, 0.011 mol) and the temperature of the heat treatment was set to 120 ° C. Aluminosilicate fine particles were produced. The dried product (dried at 100 ° C.) of the obtained sol had an amorphous structure by powder X-ray diffraction. The average particle size measured by a laser particle size distribution analyzer was 0.8 μm. When the zeta potential was measured, it was +36 mV. Next, a paint 2 comprising 60 parts of finely divided silica (trademark: Fine Seal X60, manufactured by Tokuyama Corporation), 15 parts of polyvinyl alcohol (trademark: PVA140H, manufactured by Kuraray), 15 parts of aluminosilicate fine particles obtained by the above manufacturing process, and 250 parts of water
Was prepared. The coating material 2 was applied to the high-quality paper used in Example 1 using a bar coater so as to have a dry weight of 10 g / m ² and dried to prepare an ink jet recording sheet having an ink receiving layer.

<Example 3> The procedure of Example 1 was repeated except that the amount of nitric acid in Example 1 was 4.12 g (concentration: 65%, 0.044 mol) and the temperature of the heat treatment was 120 ° C. Aluminosilicate fine particles were produced. The dried product (dried at 100 ° C.) of the obtained sol had an amorphous structure by powder X-ray diffraction. The average particle diameter measured by a laser particle size distribution analyzer was 0.5 μm. When the zeta potential was measured, it was +48 mV. Fine powder silica (Tokuyama Co., Ltd., trademark Fine Seal X6)
0) 60 parts, polyvinyl alcohol (Kuraray, trademark P
VA117) A coating material 3 comprising 10 parts, 1 part of the aluminosilicate fine particles from the above production process, and 250 parts of water was prepared.
The paint 3 was applied to the high-quality paper used in Example 1 using a bar coater so as to have a dry weight of 10 g / m ² and dried to prepare an ink jet recording sheet having an ink receiving layer.

<Comparative Example 1> On the surface of the high-quality paper used in Example 1, 60 parts of finely divided silica (trade name: Fine Seal X60, manufactured by Tokuyama Corporation) and polyvinyl alcohol (manufactured by Kuraray Co., Ltd.)
Paint 4 consisting of 20 parts of PVA124) and 250 parts of water
Was applied to the high-quality paper used in Example 1 using a bar coater so as to have a dry weight of 10 g / m ² , and dried to prepare an ink jet recording sheet having an ink receiving layer.

Comparative Example 2 60 parts of fine powdered silica (trade name: Fine Seal X60, manufactured by Tokuyama Corporation) and polyvinyl alcohol (Kuraray, manufactured by Kuraray Co., Ltd.) were applied to the surface of the high-quality paper used in Example 1.
A coating material 5 consisting of 20 parts of PVA140H) and 250 parts of water was coated on the high-quality paper used in Example 1 using a bar coater to a dry weight of 10 g / m ² , dried, and provided with an ink receiving layer. An ink jet recording sheet was prepared.

<Comparative Example 3> On the surface of the high-quality paper used in Example 1, 60 parts of finely divided silica (trade name: Fine Seal X60, manufactured by Tokuyama Corporation) and polyvinyl alcohol (manufactured by Kuraray Co., Ltd.)
Paint 6 consisting of 10 parts of PVA117) and 250 parts of water
Was applied to the high-quality paper used in Example 1 using a bar coater so that the dry weight became 10 g / m ^2, and dried to prepare an ink jet recording sheet having an ink receiving layer.

Comparative Example 4 On the surface of the high-quality paper used in Example 1, 60 parts of finely divided silica (Fine Seal X60, manufactured by Tokuyama Corporation) and polyvinyl alcohol (manufactured by Kuraray Co., Ltd.)
Trade name PVA117) 10 parts, 30 parts of aluminosilicate fine particles produced in Example 3 and 250 parts of water A paint 6 having a dry weight of 10 g / m ² was applied to the high-quality paper used in Example 1 using a bar coater. Coating and drying were performed to prepare an ink jet recording sheet having an ink receiving layer. Table 1 shows the evaluation results of these ink jet recording sheets.

[0032]

[Table 1]

As is clear from Table 1, according to the present invention, at least one surface of the support has an average particle diameter of 5 nm.
By providing an aluminosilicate fine particle having a size of about 1 μm, an ink receptive coating layer containing a filler and a binder as main components, it is possible to satisfy the uniformity of an image by ink jet recording, ink absorbency, and water resistance. Example 1
-3, the water resistance of the printed matter is reduced when no aluminosilicate fine particles are contained (Comparative Examples 1 to 3), and when the blending amount exceeds 20% by weight, the uniform ink absorption of the image is reduced (Comparative Example 4). ).

[0034]

The ink jet recording paper of the present invention has clear printing, excellent ink absorbency, uniform image quality, and excellent water resistance of printed matter, and cannot be achieved with conventional recording paper. This has the effect of enabling a high resolution, high speed, and general purpose inkjet printing system.

Claims (2)

[Claims] 1. An ink jet recording sheet provided with an ink receiving layer containing aluminosilicate fine particles, a pigment and a binder on a support, wherein the aluminosilicate fine particles are cationic and 0.5% by weight or less in the receiving layer. 20
An ink jet recording sheet characterized in that it is contained by weight%. 2. The ink jet recording sheet according to claim 1, wherein the average particle size of the aluminosilicate fine particles is 5 nm to 1 μm.