JPH09207429A - Ink jet recording image receiving body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ink jetting image receiving body wherein wrinkle and curling are not generated even when it absorbs a large quantity of solvent in an ink by providing a high-molecular porous layer having a specified oil absorption at its forming face on a synthetic paper base material and layering thereon a boehmite porous layer. SOLUTION: On a synthetic paper base material, a high-molecular porous layer is provided. The high-molecular porous layer has 3ml/m<2> or above of oil absorption obtained by increase in weight per unit area after its forming face is coated with dibutyl phthalate by a brush and its unabsorbed part is wiped away. Further thereon, a boehmite porous layer is layered so as to form an ink jet recording image receiving body. The high-molecular porous layer can be formed by coating the base material with a high-molecular aqueous latex such as a urethane resin. The boehmite porous layer has sufficient absorbency and suitable high transparency when a pore structure is formed of pores having a radius of 1-15nm and has 0.3-1.0cc/g of pore volume.

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 image receptor.

[0002]

2. Description of the Related Art In recent years, with the spread of computers and electronic still cameras, techniques for recording those images as hard copies have been developed. As a hard copy recording method, various methods such as a sublimation type thermal transfer method, an ink jet method, an electrostatic transfer type method are known in addition to a method of directly photographing a display displaying an image by silver halide photography.

An ink jet printer is
In recent years, it has become extremely popular due to its ease of full-color conversion and low printing noise. In the inkjet method, ink droplets are ejected from a nozzle toward a recording sheet at high speed, and the ink contains a large amount of solvent. Therefore, the image receptor for inkjet printers
It is required to absorb the ink quickly and have excellent color developing properties. As such an image receptor, various coated papers on the surface of which a porous layer having good absorbency is formed are known.

[0004]

In the conventional ink jet image receptor, a swellable paper that absorbs a solvent is often used as the substrate. In this case, the solvent in the ink penetrates not only into the ink receiving layer but also into the base paper. Therefore, particularly when printing is performed using an ink containing a large amount of solvent, the cellulose-based paper that is usually used as a substrate absorbs the solvent and swells, and wrinkles or curls occur on the entire image receptor (image-receiving). Body curvature) may occur. An object of the present invention is to provide an inkjet image receptor that satisfies the characteristics as an inkjet image receptor and does not cause wrinkles or curls even when a large amount of a solvent in the ink is absorbed.

[0005]

The present invention has a constitution in which a polymeric porous layer is provided on a synthetic paper substrate, and a boehmite porous layer is provided on the polymeric porous layer. The surface on which the texture layer is formed has an oil absorption of 3 ml / m ² or more obtained from the weight increase per unit area after brushing with dibutyl phthalate and wiping off the unabsorbed portion. Provide the body.

In the present invention, the oil absorption is the volume of oil that can be absorbed by the recording surface of the synthetic paper, and means the pore volume that contributes to the absorption of ink per unit area of the synthetic paper. Specifically, dibutyl phthalate (special grade reagent, specific gravity 1.05) was applied to one side of the synthetic paper with a brush, and the part that was not absorbed was wiped off, and then the weight was measured. Calculate the absorption amount.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Synthetic paper in the present invention is not a cellulosic paper obtained by making wood pulp,
The synthetic resin is made porous to have absorbency. As synthetic paper, surface processing methods such as surface treatment method and surface coating method, internal paper forming methods such as filler mixing method and stretching method,
What was manufactured by the fiber method, such as a synthetic pulp method, can be used.

The polymer porous layer formed on the synthetic paper has the effects of improving the adhesiveness between the substrate and the boehmite porous layer and improving the glossiness. Furthermore, this resin layer also contributes to the absorbability of ink. As the physical properties of the polymer porous layer,
The oil absorption measured together with the synthetic paper needs to be 3 ml / m ² or more.

As the material of the polymer porous layer, urethane resin, styrene-butadiene rubber, polyester or the like can be adopted. As a method for forming the polymer porous layer, a method of applying the above-mentioned polymer aqueous latex is preferable.

The coating amount of the polymer porous layer is 1 to 30 g / m.
^{About 2} is preferable. When the coating amount is less than 1 g / m ² , the effect of the polymer porous layer may not be sufficiently exhibited, which is not preferable. When the thickness exceeds 30 g / m ² , not only there is a problem that the strength of the polymer porous layer is lowered, but also the cost required for production is unnecessary because an unnecessary material is used, which is preferable. Absent.

It is preferable that the polymer porous layer contains inorganic particles because the absorbability can be increased.
As the inorganic particles, silica gel, hydrous silica, alumina, calcium carbonate and the like can be used. When the inorganic particles are porous, it is preferable from the viewpoint of increasing absorbency.
When adding inorganic particles, the ratio is 1 to the polymer.
50% by weight is preferred. When the content of the inorganic particles is less than 1% by weight, the effect of adding the inorganic particles is not sufficiently exhibited, which is not preferable. When the content of the inorganic particles exceeds 50% by weight, the effect of improving the adhesiveness between the substrate and the boehmite porous layer may not be sufficiently exhibited, which is not preferable.

The method for forming the polymer porous layer is preferably a method in which a polymer latex is coated with an aqueous dispersion in which inorganic particles are mixed, if necessary, and dried. As a coating means, a roll coater, an air knife coater, a blade coater, a rod coater, a bar coater, a comma coater, a die coater, a gravure coater, or the like can be used.

The ink jet recording image receptor of the present invention comprises:
It has a boehmite porous layer as an ink receiving layer. Boehmite has a composition formula of Al ₂ O ₃ .nH ₂ O (n = 1 to 1.
The particles shown in 5) are excellent in terms of ink absorption, dye fixing, and the like, and since the transparency of the ink receiving layer is good, the color density at the time of recording is high and the texture of the substrate is also good. It is particularly preferable because it does not damage.

When the boehmite porous layer contains an organic binder, it is preferable because the porous layer is excellent in mechanical strength. As the binder, starch and its modified products, polyvinyl alcohol and its modified products, SBR latex, NBR latex, carboxymethyl cellulose,
Organic substances such as hydroxymethyl cellulose and polyvinylpyrrolidone can be used. The amount of binder used is preferably about 5 to 50% by weight of boehmite. If the amount of binder used is less than 5% by weight,
The strength of the ink receiving layer may be insufficient, and if it exceeds 50% by weight, the ink absorbency may be insufficient, which is not preferable. A particularly preferred amount of binder is 5 to 15% by weight of boehmite.

When the pore structure of the boehmite porous layer is substantially composed of pores having a radius of 1 to 15 nm and the pore volume is 0.3 to 1.0 cc / g, sufficient absorbability is obtained. It is preferable because it has a high transparency and high transparency. When the transparency of the ink receiving layer is high, the coloring of the dye is good when the ink is absorbed. The pore radius distribution is measured by the nitrogen adsorption method.

The coating amount of the ink receiving layer is 0.
It is preferably in the range of 1 to 100 g / m ² . When the coating amount of the ink receiving layer is less than 0.1 g / m ² ,
It is not preferable because the fixability and absorptivity of the dye may become insufficient and clear recording with high color density may not be possible. When the coating amount of the ink receiving layer exceeds 100 g / m ² , the mechanical strength of the ink receiving layer may decrease, or the transparency may decrease and the color density of the recorded matter may decrease, which is not preferable. . The more preferable thickness of the ink receiving layer is 5
˜50 μm.

As a means for providing an ink receiving layer on a substrate, for example, a binder is added to alumina sol to form a slurry, and a roll coater, air knife coater, blade coater, rod coater, bar coater, comma coater, die coater, gravure coater is used. It is possible to employ a method of applying and drying by using the above.

When the silica gel layer is provided on the boehmite porous layer, scratch resistance is improved as compared with the case where the boehmite porous layer is used alone, which is preferable. The silica gel layer is permeable to the ink when it is applied.

The silica gel layer can be firmly adhered to the surface of the sheet by preferably dispersing silica sol in a binder solution, coating and drying. The silica sol has an average particle diameter of 10 to 90 nm,
It is preferable to use one having a solid content concentration of 1 to 20% by weight. As the binder to be mixed with the silica sol, the same binder as used for the boehmite porous layer can be used, but it is particularly preferable to use a silicon-containing polymer such as silicon-containing polyvinyl alcohol. The amount of the binder used is preferably 1 to 30% by weight based on the solid content of the silica sol (converted to SiO ₂ ).

The thickness of this silica gel layer is 0.1 to 30.
It is preferably about μm. Thickness of silica gel layer is 0.1μm
If it is less than the above range, the effect of improving the scratch resistance is insufficient, which is not preferable. When the thickness of the silica gel layer exceeds 30 μm, the transparency of the ink receiving layer may be impaired, which is not preferable.

[0021]

EXAMPLES The oil absorption amount in the examples was measured as follows. Dibutyl phthalate (special grade reagent, specific gravity 1.05)
With a brush on an image receptor cut into 5 cm x 20 cm,
The non-absorbed part was wiped off and weighed. The amount of absorption per unit area was calculated from the increase in weight.

Example 1 Polyester urethane latex having a solid content of 50% by weight (trade name: Hydran HW-9, manufactured by Dainippon Ink and Chemicals, Inc.)
30) 100 parts by weight and 40 parts by weight of styrene-butadiene rubber latex (manufactured by Zeon Corporation, trade name Nipol LX407BP) having a solid content of 50% by weight were mixed to prepare a latex coating solution. This coating liquid was used for oil absorption of 11 g /
60 m ² of synthetic paper (manufactured by Nisshinbo Industries Inc., trade name Peachcoat WE-110) was applied using a bar coater.
A polymer porous layer was formed by drying and baking in an oven at ℃ for several minutes. The coating amount of this polymer porous layer is 7 g /
cm ² and the oil absorption including the polymer porous layer is 14 m
It was 1 / m ² .

Alumina sol 1 having a solid content of 18% by weight synthesized by the hydrolysis / peptization method of aluminum isopropoxide
00g and polyvinyl alcohol 6.2 weight% aqueous solution 32
A coating liquid obtained by mixing with g was prepared. This coating liquid was applied onto the above polymer porous layer using a bar coater, dried and baked in an oven at 60 ° C for several minutes to form a boehmite porous layer. The coating amount of this boehmite porous layer was 20 g / m ² .

Example 2 An image receptor was produced in the same manner as in Example 1 except that a synthetic paper having an oil absorption of 4 ml / m ² (manufactured by Oji Yuka Synthetic Paper Co., Ltd., trade name YUPO VIF-90) was used as the base material. did. The oil absorption of the base material including the polymer porous layer was 7 g / m ² , and the coating amount of the boehmite porous layer when dried was 20 g / m ² .

Example 3 (Comparative Example) The synthetic paper of Example 1 was coated with 20 g / m ² of boehmite porous material without forming a polymer porous layer to form an image receptor.

Example 4 (Comparative Example) The synthetic paper of Example ² was coated with 20 g / m ² of boehmite porous material without forming a polymer porous layer to form an image receptor.

Example 5 (Comparative Example) A polyester film having no oil absorbency was used as a substrate, and boehmite porous material was coated at 20 g / m ² to form an image receptor.

[0028] Examples using 6 commercial form paper (Comparative Example) substrate (basis weight 68 g / m ^2), to form the image receptor boehmite porous and coated with 20 g / m ^2. The oil absorption of this foam paper is 25 ml / m ²
Met.

Characteristic Evaluation With respect to the image receivers of Examples 1 to 6, the glossiness was set to 60 ° in both the incident angle and the reflection angle, and a gloss meter (trade name: VGS-300A manufactured by Nippon Denshoku Kogyo Co., Ltd.) was used. Measured. The adhesiveness of the boehmite porous material was evaluated by a cellophane tape peeling test. Inkjet printer (Seiko Epson Corporation, trade name MJ
-5000C), the following test patterns were printed and evaluated. Three 3 cm × 4 cm rectangles were arranged adjacent to each other in a line, and three colors (color mixture black, red (magenta + yellow 200% color mixture), green (cyan + magenta 200% color mixture)) were printed in order. The absorbability was evaluated based on the bleeding that can be visually observed. Regarding the formation, the presence or absence of wrinkles immediately after printing was visually evaluated in the 200% mixed color portion in the above test pattern. Table 1 shows the results. In Table 1, the adhesiveness, the absorbability, and the formation are shown in the following three relative evaluations. ○:
Particularly good, Δ: good, ×: poor.

[0030]

[Table 1]

[0031]

The ink jet recording image receptor of the present invention has high ink absorption and high dye adsorption, and
No wrinkles occur when recording with ink containing a large amount of solvent.

Claims (3)

[Claims] 1. A structure having a polymer porous layer on a synthetic paper substrate, and a boehmite porous layer on the polymer porous layer, wherein the surface of the synthetic paper substrate on which the polymer porous layer is formed is: The oil absorption amount calculated from the weight increase per unit area after brushing with dibutyl phthalate and wiping off the unabsorbed part was 3 m
An ink jet recording image receptor having a l / m ² or more. 2. The ink jet recording image receptor according to claim 1, wherein inorganic particles are dispersed in the polymer porous layer. 3. The ink jet recording image receptor according to claim 1, which further comprises a silica gel layer on the boehmite porous layer.