JP2003170654A - Ink jet recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high quality ink jet recording medium, which has no coating defect such as orange peeling or the like, is remarkably excellent in ink absorbency and color developing properties and has a dull-tone glossiness. <P>SOLUTION: In the ink jet recording medium, which is formed at least one recording layer on at least one side of a support, at least one layer in the recording layers is a recording layer mainly made of a colloidal silica and a cationic chemical. Further, the amount of an anion included in the colloidal silica is 0 to 400 ppm. <P>COPYRIGHT: (C)2003,JPO

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 medium, and in particular, it has a high-grade dull-like glossy feeling with good image reproducibility so that it can be used for proofing printed matter, and has good ink absorbability. In addition, the present invention relates to an inkjet recording medium suitable for a photo-type inkjet printer that ejects a large amount of ink.

[0002]

2. Description of the Related Art Ink jet recording systems have become popular rapidly in recent years due to their ease of full-color printing and low print noise. In this method, ink droplets are ejected from a nozzle toward a recording medium at high speed, and the ink contains a large amount of solvent. Therefore, it is necessary for the recording medium to quickly absorb the ink. Also. With the recent widespread use of computers and digital cameras, images close to those of silver halide photographs have been demanded. Therefore, the inkjet recording medium is required to have high color developability, resolution and color reproducibility.

In order to obtain an image close to a silver salt photograph having high color developability, resolution and color reproducibility by an ink jet recording system, it has been customary to give a recording paper gloss. As a conventional technique for obtaining a glossy inkjet recording paper, a particle diameter of 300 nm on an ink receiving layer is disclosed in JP-A-7-101142.
The following layer of colloidal particles is provided to give a 75 degree specular gloss of 2
A method of imparting a glossiness of 5% or more, and JP-A-9-1
A method of providing two or more ink receiving layers containing colloidal silica and an adhesive on a support as described in JP-A-83265, or JP-A-3-215080, JP-A-3-256785, and JP-A-7-78578. There is disclosed a method in which two or more ink receiving layers are provided and the upper layer is used as a gloss developing layer, as described in JP-A-89220 and JP-A-7-117335. The present inventors also have a support,
An ink jet recording paper comprising an ink absorbing layer and a colloidal silica layer, which are sequentially provided on the support, has already been proposed (JP-A 2000-190626).

By the way, in order to fix the dye on the ink receiving layer on the ink jet recording medium to satisfy the water resistance of the printed portion, a cationic chemical is added as an ink fixing agent. However, when a cationic chemical is mixed with anionic colloidal silica, there is a problem in that paint shock is likely to occur. As a solution to this problem, there is a method in which the pH of colloidal silica is made acidic, which makes it possible to mix it with a cationic polymer. However, in this case, the thixotropy of the paint increases, and when the paint stays thickened and bubbles are more likely to be clogged in the paint, as a result, when coating colloidal silica, it is called foam baldness The coating defects that are considered to be caused by the bubbles of the above are likely to occur. Therefore, the inventors of the present invention described in JP 2000
In the ink jet recording paper and the like disclosed in JP-A-190626, further improvement has been desired from the viewpoint of workability.

[0005]

Therefore, the present inventors
Recording layer containing anionic colloidal silica and cationic chemicals, as a result of intensive studies to eliminate the baldness of bubbles generated during coating, by setting the amount of anions contained in the colloidal silica to 400 ppm or less, The inventors have found that the viscosity of the coating can be suppressed and the occurrence of coating defects caused by bubbles can be prevented, and the present invention has been completed. Therefore, an object of the present invention is to provide a high-quality inkjet recording medium which has not only a coating defect caused by bubbles but also has a dull tone glossiness which has a high color density and is excellent in color reproducibility. is there.

[0006]

The above objects of the present invention are as follows.
An inkjet recording medium in which at least one recording layer is provided on at least one surface of a support, and at least one layer of the recording layer is a recording layer containing colloidal silica and a cationic drug as main components, This has been achieved by an ink jet recording medium characterized in that the amount of anions contained in the colloidal silica is 0 to 400 ppm based on the total amount of colloidal silica.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. The support used in the present invention is not particularly limited and may be transparent or opaque. For example, plastic films such as cellophane, polyethylene, polypropylene, soft polyvinyl chloride, hard polyvinyl chloride, polyester, fine paper, photographic paper base paper, drawing paper, painting paper, art paper, coated paper, cast coated paper, kraft paper , Impregnated paper, synthetic paper, and the like, which can be appropriately used according to the application. In the present invention, it is particularly preferable to use a support having ink absorbability.

The ink jet recording material of the present invention contains at least colloidal silica and a cationic chemical in the recording layer. Hereinafter, each chemical will be described. As the colloidal silica used in the gloss-developing layer, various shapes such as spherical or chain-like can be used, but in the present invention, particularly chain colloidal silica, that is, spherical colloidal silica that is a primary particle is used. Colloidal silica having a specific number, which is connected in series or partially branched, is preferably used. The chain colloidal silica preferably has primary particles of 3 to 40 nm. It is difficult to stably produce primary particles having a particle size of less than 3 nm, and if the particle size exceeds 40 nm, the chain colloidal silica has a small specific surface area.
That is, the color density and color reproducibility are insufficient.

The anion in the colloidal silica used in the present invention must be 0 to 400 ppm.
It is more preferably from 0 to 300 ppm. When the amount of anion is more than 400 ppm, the reaction between the anion and the cationic chemical causes the paint to thicken and hinder the foam, which lowers the coating suitability of the coating and tends to cause coating defects due to the foam. . The anion referred to here is, for example, a by-product (impurity) generated in the manufacturing process of colloidal silica.
It is a generic term for anions such as nitrate ion, sulfite ion, chloride ion, etc. without being removed by a method using a microporous membrane such as an ultrafiltration membrane or a reverse osmosis membrane or a method using an ion exchange resin. , Which remains in the colloidal silica. The ion amount is measured by using the ion chromatography method.

Next, the cationic chemical will be described. The cationic chemical used in the present invention is not particularly limited, and those generally known as dye fixing agents for inkjet recording paper can be used. That is, these are secondary amines, which form insoluble salts with sulfonic acid groups, carboxyl groups, amino groups, etc. in water-soluble direct dyes and water-soluble acid dyes contained in water-based dye inks, and 3
It contains a primary amine or a quaternary ammonium salt. You may use these cationic compounds individually or in combination of 2 or more types. The amount of cationic chemicals used is preferably 0.1 parts by weight to 20 parts by weight, particularly 1 part by weight to 100 parts by weight of colloidal silica.
It is preferably 10 parts by weight. When the amount of the cationic chemical used is less than 0.1 parts by weight, the ink cannot be sufficiently fixed in the recording layer, and when it is more than 20 parts by weight,
Another problem arises, such as the yellowing of paper from cationic agents.

The colloidal silica used in the ink jet recording medium of the present invention has a binding force by itself, and thus does not necessarily require any other binder, but it may be used if necessary. As the binder, for example, water-soluble polymers such as polyvinyl alcohol, casein, starch and gelatin, or water-dispersible polymers such as styrene-butadiene latex, acrylic latex and vinyl acetate latex can be used. . The amount of the binder used is preferably 0 part by weight to 10 parts by weight, more preferably 0 part by weight to 100 parts by weight of colloidal silica.
It is preferably 5 parts by weight. The amount of binder used is 10
Although the surface strength increases when the amount is more than the weight part, on the other hand,
Ink absorbency and gloss decrease.

In the recording layer of the ink jet recording medium of the present invention, to the extent that the effects of the present invention are not impaired, sizing agents, defoaming agents, tint adjusting agents, coloring dyes, coloring pigments, fluorescent dyes, and ultraviolet absorbers. , Antioxidant, antiseptic, water resistant,
Various additives such as surfactants and wet strength agents can be added. In any case, the proportion of colloidal silica in the colloidal silica layer is preferably 90% by weight or more, and the colloidal silica is particularly preferably chain colloidal silica.

Further, in order to further improve the ink absorbency of the ink jet recording medium of the present invention, it is preferable to provide an under layer functioning as an ink receiving layer between the colloidal silica layer and the support. As the pigment used for the under layer, synthetic silica, alumina or alumina hydrate (alumina sol, colloidal alumina, pseudo-boehmite, etc.), aluminum silicate, magnesium silicate, magnesium carbonate, light calcium carbonate, heavy calcium carbonate,
In addition to inorganic pigments such as kaolin, talc, calcium sulfate, titanium dioxide, zinc oxide, zinc carbonate, calcium silicate, and aluminum hydroxide, plastic pigments,
Organic pigments such as urea resins can also be used. Further, as the binder for the under layer, the same binder as used for the above-mentioned ink receiving layer is preferably used.

Further, in any coating layer, the ink jet recording medium of the present invention further comprises a pigment dispersant, a thickener, a defoaming agent, a foam suppressor, a release agent, a foaming agent, a coloring dye and a coloring agent. Pigments, fluorescent dyes, ultraviolet absorbers, antioxidants, preservatives,
A water resistant agent, a surfactant, a wet paper strength enhancer and the like can be appropriately contained within a range that does not impair the effects of the present invention. When providing the ink receiving layer on the surface of the support, various coating devices which are general coating devices such as a blade coater, a roll coater, an air knife coater, a bar coater, a gate roll coater, a curtain coater, a short dwell coater, a gravure coater, and a flexogravure are used. Coater,
Various devices such as size presses can be used on-machine or off-machine. In the present invention, it is also possible to perform surface treatment with a calendar device such as a machine calendar, a super calendar or a soft calendar before or after coating each layer.

[0015]

In the present invention, since colloidal silica having a reduced amount of anions is used, the viscosity of the coating does not increase even when a cationic chemical is present. Therefore, the ink jet recording medium of the present invention is an extremely high quality recording medium because defects such as baldness of bubbles caused by applying a highly viscous coating material do not occur.

[0016]

EXAMPLES The present invention will be described in more detail with reference to the following examples.
However, the present invention is not limited thereto.
is not. In addition, the compounding parts and% in the examples are not particularly specified.
Unless otherwise indicated, they are parts by weight and% by weight, respectively. Example 1.Preparation of support 85 parts of LBKP with a freeness of 380 ml and a freeness of 500 m
15 parts of NBKP, 15 parts of talc as a filler,
Commercially available rosin-based sizing agent 0.5 part, commercially available cationization
0.3 parts starch, 0.5 parts sulfuric acid band, and market
Add 0.1 parts of paper strength enhancer to water and add 0.8% slurry.
After making the lee, using a Fourdrinier paper machine, the basis weight is 130 g / m
^TwoIt was made into paper.

[0017]Preparation and coating of color for ink absorption layer Synthetic amorphous silica (Fineseal X37B, Soda Tokuyama)
100 parts, polyvinyl alcohol (PVA117,
Kuraray) 25 parts, ethylene vinyl acetate copolymer Emul
(Sumikaflex 401, Sumitomo Chemical) 10
Part, nonionic SB latex (LX438C, Nippon Ze
5 parts, dye fixing agent (PAS-H10L, Nittobo)
8 parts, antifoaming agent (SN deformer 480, Sanno)
0.2 parts by Puko Ltd., cationic sizing agent (Polymaron)
360, Arakawa Chemical Co., Ltd.) 3 parts, bluing agent 0.0
05 parts and 0.5 parts of fluorescent dye were added to water to give a solid content.
An ink absorbing layer color having a density of 20% was produced. this
The weight of the color on the above-mentioned support after drying is 15 g /
m^TwoCoated with a bar blade coater so that
Scuff dryer until the total moisture content reaches 4.5%
-Coated paper that has an ink absorption layer as a coating layer
Got

[0018]Coating of colloidal silica layer The amount of anions is 10 p on the ink absorption layer of the above coated paper.
Chain colloidal silica having a particle size of 110 nm in pm 10
0 parts, 6 parts of cationic dye fixing agent, and silicone antifoaming agent
A coating solution of 16% concentration mixed with 0.2 parts was applied to a bar breaker.
Using a coater, the weight after drying is 2g / m^TwoWill be
Apply seaweed and dry until the water content is 4.5%.
One colloidal silica layer was used. Next, the second colloidal
As a liquid layer, the above 16% coating solution
2 g / m after dried with a coater^TwoSo that
To the moisture content of 4.8%, and then
Condition of linear pressure of 100 kg / cm with a soft calendar device
Finished surface treatment is performed with a 75 degree specular gloss of 33%.
A recording sheet for ink jet was obtained.

Example 2. Instead of the chain-like colloidal silica used in Example 1, chain-like colloidal silica having an anion amount of 200 ppm and a particle diameter of 110 nm was used in the same manner as in Example 1, and the 75-degree specular gloss was 33. % Of ink jet recording paper was obtained.

Example 3. The chain colloidal silica used in Example 1 was replaced with chain colloidal silica having an anion amount of 360 ppm and a particle size of 110 nm in the same manner as in Example 1 except that the chain colloidal silica had a 75-degree specular gloss of 33. % Of ink jet recording paper was obtained.

Comparative Example 1. The chain colloidal silica used in Example 1 was replaced with chain colloidal silica having an anion amount of 550 ppm and a particle size of 110 nm, in the same manner as in Example 1, except that the 75 degree specular gloss was 34. % Of ink jet recording paper was obtained.

Comparative Example 2. An inkjet recording paper having a 75-degree specular gloss of 35% was obtained in exactly the same manner as in Comparative Example 1 except that the cationic dye fixing agent was not added in the preparation of the coating liquid of Comparative Example 1.

The recording papers obtained in the above Examples 1 to 3 and Comparative Examples 1 and 2 were subjected to various evaluations by the following methods. 1) Paint viscosity The paint viscosity of the above colloidal silica layer is determined according to JIS-K-71.
According to No. 17, it was measured with a BM type viscometer manufactured by TOKIMEC. 2) Coating defects The coated surface of the obtained paper was observed with the naked eye, the number of coating defects (bubble baldness) was counted, and evaluated according to the following criteria. ◯: Almost no coating defects (foam baldness) are recognized (0 to
Less than 1 / m ² ). Δ: Coating defects (foam baldness) are slightly recognized (1 to less than 3 pieces / m ² ). X: Significant coating defects (foam baldness) are recognized (3 or more / m ² ). 3) Color-forming Seiko Epson inkjet printer PM
Using -800C, spreadsheet software "Excel", black (BK), cyan (C), magenta (M), yellow (Y)
Create a solid image of, set the printer driver attached to the printer, and use photo print paper for paper.
For the mode settings, we selected the recommended settings (clean) and printed them out. After leaving it in a constant temperature and humidity room for 24 hours, a Macbeth densitometer (RD915, Macbet
(manufactured by Company H) was used to measure the print density of each color, and the average value was used as the average density. ◯: Average density is 1.8 or more Δ: Average density is in the range of 1.6 or more and less than 1.8 ×: Average density is less than 1.6 4) Surface strength Sellotape (registered) on the recording surface. Trademark), rub it 20 times with a rubber roller, and fix the end part only to the spring to 180
The peel strength in the direction of ° was measured and evaluated according to the following criteria. ◯: Peel strength is 500 gf or more Δ: Peel strength is in the range of 300 gf or more and less than 500 gf ×: Peel strength is less than 300 gf 5) Image water resistance Seiko Epson inkjet printer PM
Using -800C, spreadsheet software "Excel", black (BK), cyan (C), magenta (M), yellow (Y)
Create a solid image of, set the printer driver attached to the printer, and use photo print paper for paper.
For the mode settings, we selected the recommended settings (clean) and printed them out. The printed matter was immersed in running water for 5 minutes and then naturally dried, and the ink flow condition was visually evaluated. ◯: Almost no ink flowed out Δ: Ink flowed out slightly ×: Ink flowed out significantly 6) 75 degree glossiness In accordance with JIS-P-8142, Murakami Color Research Laboratory specular gloss meter ( GM-26for75 degree). The results are shown in Table 1. In the table, there is no practical problem if the evaluation is ◯ or Δ, but there is a practical problem when the evaluation is ×.

[Table 1]

As is clear from the results shown in Table 1, in Examples 1 to 3 of the present invention, by decreasing the amount of anions in the chain-like colloidal silica, the viscosity of the coating composition increased when the cationic chemical was used in combination. It has been demonstrated that is reduced. Further, as a result, it is apparent that coating defects caused by bubbles are reduced and the operability is improved. Furthermore, from the results of Comparative Examples 1 and 2, it is clear that the thickening and coating defects of the coating material are due to the mixing of the anion in the colloidal silica and the cationic fixing agent. It was confirmed that when not used in the liquid, it is good in terms of thickening of the paint and coating defects, but practically causes problems in terms of water resistance of the image. From these results, by providing a layer containing a colloidal silica having a reduced amount of anions and a cationic chemical as a main component in the recording layer, an inkjet ink having a high dull tone and excellent color reproducibility and having a dull tone glossiness. It was demonstrated that the recording paper can be manufactured and that it has high practical value.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Susumu Hagisawa             5-21-1 Oji, Kita-ku, Tokyo Nippon Paper Co., Ltd.             Company Product Research Center (72) Inventor Yoshihiro Kuroyama             5-21-1 Oji, Kita-ku, Tokyo Nippon Paper Co., Ltd.             Company Product Research Center F-term (reference) 2C056 EA04 FB02 FC06                 2H086 BA16 BA33 BA35 BA41

Claims (3)

[Claims] 1. An inkjet recording medium having at least one recording layer on at least one surface of a support, wherein at least one layer in the recording layer contains colloidal silica and a cationic drug as main components. While being a recording layer,
An inkjet recording medium, wherein the amount of anions contained in the colloidal silica is 0 to 400 ppm with respect to the total amount of colloidal silica. 2. The ink jet recording medium according to claim 1, wherein a layer containing colloidal silica and a cationic polymer as main components is provided as an outermost layer. 3. The inkjet recording medium according to claim 1, wherein the colloidal silica is a chain colloidal silica.