JPH06191146A - Ink jet recording paper - Google Patents

Abstract

PURPOSE:To provide aqueous ink jet recording paper capable of performing recording of high image quality. CONSTITUTION:Ink jet recording paper is obtained by providing a coating layer based on pigment and an aqueous adhesive and containing a spiro 6-membered ring boric triester compd. on at least one surface of base paper based on cellulose pulp as an ink receptive coating layer in a coating amt. of 2-10g/m<2>. By this constitution, plain paper like ink jet recording paper imparting sharp printing, excellent in ink absorbability, eliminating the defect of conventional recording paper by improving the uniformity of printing density and resolving power and having a high grade and high resolving power is provided.

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 for use in printers, copying machines and the like using water-based ink, and more particularly, an improved color ink jet printer recording having excellent characteristics of color development and image uniformity. It is about paper.

[0002]

2. Description of the Related Art Ink jet printers that use water-based inks have improved performance, and particularly improved image quality such as print speed, resolution, gradation, and the like. In addition to the above, there has been a demand for a color ink jet recording paper which is uniform in density and has printing characteristics of higher image quality, and which has a low coating amount of the ink receptive coating layer and is like a plain paper.

For example, JP-A-55-51583 discloses that a coating layer comprising non-colloidal silica and a polymer binder is provided in order to accelerate ink absorption and print at high density. Japanese Unexamined Patent Publication (Kokai) No. 62-144986 discloses the use of a surfactant whose HLB is in a specific range as a method for improving ink absorbency, particularly at low temperature and low humidity. Further, JP-A-62-146784 describes that the use of a fluorine-based surfactant and acidic gelatin improves the uniformity of the density and the unevenness of the printed area due to water droplets. JP-A-162275 describes that by containing a cationic surfactant and a cationic polymer, water resistance is maintained, and color rubbing and ink bleeding are improved. Consideration of measures has been made.

However, an ink-receptive coating layer having a low coating amount, which is capable of high-density and uniform high-quality printing, has a high ink absorption speed, does not impair the coloring of dyes, and has a high image resolution, is usually used. There is still no satisfactory paper-like color inkjet recording paper.

[0005]

SUMMARY OF THE INVENTION The present invention relates to an ink jet printer using an aqueous ink, which has a high ink absorption speed, a large absorption capacity, and a sharp high resolution image which can be printed at a high speed. It is an object of the present invention to provide an inkjet recording paper which is excellent in density uniformity and which solves the above-mentioned drawbacks of the prior art.

[0006]

As a result of various investigations by the present inventors to solve the above-mentioned drawbacks, the main components are a pigment and an aqueous adhesive, and boric acid having a specific structure. By providing an ink-receptive coating layer containing a triester compound on at least one surface of a support containing cellulose pulp as a main component, it is possible to print at a high density, with excellent density uniformity and ink absorption. The inventors have found that an ink jet recording paper having good properties and excellent storage properties such as surface strength, water resistance and light resistance can be obtained, and completed the present invention.

According to the present invention, a coating layer containing a pigment and an aqueous adhesive as main components is formed as an ink-receptive coating layer on at least one surface of a base paper containing cellulose pulp as a main component,
The present invention relates to an inkjet recording paper, wherein the ink-receptive coating layer contains a spiro six-membered ring boric acid triester compound and the coating amount is ² to 10 g / m ² .

In general, when an ink-receptive coating layer containing a pigment and an aqueous adhesive as a main component is provided on at least one surface of a base paper containing a cellulose pulp as a main component, the influence of the base material becomes remarkable when the coating amount decreases. For example, when paper is used as the base material, the unevenness of the fibers and fillers inside the base paper, the smoothness of the base paper surface, and the difference in size are caused by the distribution of the wettability during coating, the change in absorbency, and the ink. Affects the uniformity of the receptive coating. In particular, it is not so noticeable in character printing, but when printed in a plane, it is perceived as density unevenness and the printing quality is significantly deteriorated. Such non-uniformity of printing can be eliminated by increasing the coating amount, but it is not desirable because the coating layer becomes thick and the feeling of plain paper is impaired, and the cost increases.

In the present invention, the base paper is preferably used as the support, but a plastic film or synthetic paper can be used as the support, if necessary. When applying a water-based paint to such a non-absorbing base material, coating defects such as cissing and pinholes will occur and the image quality will be degraded, so substances such as wetting agents that have surface-active properties are generally added. It has been carried out to improve the coatability, and the addition of such substances causes problems such as coating strength, deterioration of water resistance strength, and deterioration of resolution. Is also effective for improvement.

The pigment used in the ink-receptive coating layer of the present invention is preferably one which gives a clear image when used in ink jet recording, and silica, aluminum silicate,
Inorganic pigments such as calcium silicate, kaolin, clay, light calcium carbonate, heavy calcium carbonate, magnesium carbonate, aluminum hydroxide, diatomaceous earth, zinc oxide, titanium oxide, barium sulfate and acid clay, urea resin pigment, ethylene resin Pigments, styrene resin pigments, acrylic resin pigments, and other organic pigments,
These may be used alone or in combination of two or more.

The aqueous adhesive used in the ink-receptive coating layer of the present invention includes a derivative modified with polyvinyl alcohol and silanol groups, oxidized starch, and modified starch such as etherification, esterification and grafting. Cellulose derivatives such as gelatin, casein, carboxymethyl cellulose, polyvinylpyrrolidone, water-soluble adhesives such as water-soluble polyester resin and styrene / butadiene copolymers, acrylic ester copolymers, polyvinyl acetate, ethylene / vinyl acetate copolymers Water-dispersible adhesives such as coalesced are used alone or in combination.

The spiro six-membered boric acid triester compound used in the present invention is, for example, JP-A-51-146485.
JP-A-51-149474 and the like, and specifically, the compound represented by the general formula (1).

[0013]

[Chemical 1]

In the general formula (1), -R is a carbon number of 1 to
4 alkyl groups, R'and R "are hydrogen atoms, CH ₃ -groups or C ₂ H ₅ -groups X, X ', X", Y, Y'and Y "are hydrogen atoms, CH ₃ -groups, C ₂ H ₅ - group, C ₃ H ₇
Group or either of X'and Y'is CH ₃ O
- group, C ₂ H ₅ O-group, CH ₃ OCH ₂ - group, and C ₂ H
_{It is a 5} -group and shows a positive number of m and n2-6.

Typical compounds included in the spiro six-membered boric acid triester compound represented by the above general formula include the following compounds.

[0016]

[Chemical 2] [Methoxy (diethyleneoxy) ethyl = butylene-
1,3-] = borate

[0017]

[Chemical 3] [Methoxy (diethyleneoxy) isopropyl = butylene-1,3-] = borate

[0018]

[Chemical 4] [Ethoxyethyleneoxyethyl = 2-ethoxypropylene-1,3-] = borate

[0019]

[Chemical 5] [Ethoxy (diethyleneoxy) ethyl = 2-methylamylene-2,4-] = borate

[0020]

[Chemical 6] [Isopropoxy (triethyleneoxy) ethyl = 2-
Methyl amylene-2,4-] = borate

[0021]

[Chemical 7] [Methoxyethyleneoxyethyl = butylene-1,3
-] = Borat

The spiro six-membered ring boric acid triester compound used in the present invention is a semipolar organic boron compound having a polar portion and a non-polar portion in the molecule, and an organic solvent,
It has solubility in water and exhibits surface activity. In addition to having the ability to dissolve cationic dyes and acid dyes, the semi-polar part of the spiro six-membered boric acid triester compound exhibits an appropriate thickening effect by interacting with the hydroxyl groups in the paint, and the coatability is In addition to improving and reducing coating defects such as cissing and pinholes, it shows a gradual crosslinking effect in the coating film after drying,
It is considered that this is the result of maintaining the strength without lowering the ink absorptivity and color developability, as compared with the case of adding an ordinary liquid surfactant.

In the ink jet recording paper of the present invention, the ink receptive coating layer further comprises an additive,
A pigment dispersant, a defoaming agent, a colorant, an antioxidant, an ultraviolet absorber, a viscosity modifier, a cross-linking agent, etc. are appropriately used according to the production conditions, printing quality and required performance.

The amount of the pigment used in the ink-receptive coating layer of the present invention is in the range of 40 to 90% by weight, preferably 50 to 80% by weight. If the pigment is used in an amount of more than 90% by weight, the strength will be decreased, which is not preferable. Also, 40% by weight
If it is below the range, the ink absorbency is lowered, the ink drying property is insufficient, and the image quality is lowered.

The spiro six-membered boric acid triester compound is preferably used in the range of 0.1 to 5% by weight,
Even if it exceeds 5% by weight, further improvement of the effect cannot be expected. Further, if it is less than 0.1% by weight, the effect is not sufficiently exhibited.

In the ink-receptive coating layer of the present invention, the above-mentioned constituents are uniformly dispersed in water by a conventional method to prepare a coating solution, which is used in, for example, a bar coater, a blade coater, an air knife coater, a gravure coater or the like. The coating amount is 2 to 20 g / m on at least one surface of the support by the coating method.
It is formed in the range of ² . If the coating amount is less than 2 g / m ² , the image and the uniformity and the image density will be insufficient.
If it is more than g / m ² , not only the coating strength will decrease, but also
High price, which is not preferable.

The sheet-like support used in the present invention is mainly composed of ordinary natural pulp, such as high-quality paper, medium-quality paper,
Recycled paper is used. The thickness of the sheet-shaped support is 10 to
It is preferably 200 μm and the basis weight is 10 to 200 g / m ² .

Hereinafter, the present invention will be described in more detail with reference to Examples, but of course the present invention is not limited thereto. In the examples,% means% by weight in terms of solid content.

[0029]

EXAMPLES Example 1 paint -1 adjusted to a concentration 18 wt%, the coating at a rate of 5 g / m ² by solid content in the wood-free paper of 65 g / m ² Engineering, dried, the ink receptive coating layer An ink jet recording sheet was prepared.

The paint -1 Ingredient Weight amorphous fine silica powder (FINESIL: Tokuyama Soda Co., Ltd.) 80.0% Polyvinyl alcohol (PVA124: Kuraray Ltd.) 18.0% (methoxy ethyleneoxy ethyl = butylene -1, 3 −) = Borate (Emulbon BDB: manufactured by Toho Chemical Industry) 0.5% Sodium polyacrylate (dispersant: manufactured by Toagosei) 1.5%

[0031] Example 2 coating dispersion 2 was prepared in the concentration of 18 wt%, the coating at a rate of 5 g / m ² by solid content in the wood-free paper of 5 g / m ^2, and dried, with an ink receptive coating layer An inkjet recording sheet was prepared.

[0032] Paint -2 Ingredient Weight calcium carbonate (Brilliant 15: Shiraishi Chemical Industry Ltd.) 78.5% Polyvinyl alcohol (PVA124: Kuraray Ltd.) 18.0% Emarubon BDB (manufactured by Toho Chemical Industry) 2.0% poly Sodium acrylate (dispersant: Toagosei) 1.5%

[0033] Example 3 paint -3 adjusted to a concentration 18 wt%, the coating at a rate of 5 g / m ² by solid content in the wood-free paper of 65 g / m ^2, dried, with an ink receptive coating layer An inkjet recording sheet was prepared.

[0034] Paint -3 Ingredient Weight amorphous fine silica powder (FINESIL: manufactured by Tokuyama Soda) 79.5% silanol-modified polyvinyl alcohol (R-1130: manufactured by Kuraray) 18.0% Emarubon BDB (Toho Chemical Industry Made) 1.0% sodium polyacrylate (dispersant: made by Toagosei) 1.5%

[0035] Comparative Example 1 Paint -4 adjusted to a concentration 18 wt%, the coating at a rate of 5 g / m ² by solid content in the wood-free paper of 65 g / m ^2, dried, with an ink receptive coating layer An inkjet recording sheet was prepared.

[0036] Paint -4 Ingredient Weight amorphous fine silica powder (FINESIL: Tokuyama Soda Co., Ltd.) 82.5% silanated polyvinyl alcohol (R-1130: manufactured by Kuraray Co.) 16.5% sodium polyacrylate 1.0 %

[0037] Comparative Example 2 Paint -5 adjusted to a concentration 18 wt%, the coating at a rate of 1 g / m ² by solid content in the wood-free paper of 65 g / m ^2, and dried, with an ink receptive coating layer An inkjet recording sheet was prepared.

The paint -5 Ingredient Weight calcium carbonate (Brilliant 15: Shiraishi Chemical Industry Ltd.) 79.5% Polyvinyl alcohol (PVA124: Kuraray Ltd.) 18.0% Emarubon BDB (manufactured by Toho Chemical Industry) 1.0% poly Sodium acrylate 1.5%

[0039] Comparative Example 3 paint -6 adjusted to a concentration 18 wt%, the coating at a rate of 5 g / m ² by solid content in the wood-free paper of 65 g / m ^2, and dried, with an ink receptive coating layer An inkjet recording sheet was prepared. Ingredient Weight amorphous fine silica powder (FINESIL: Tokuyama Soda Co., Ltd.) 79.5% silanated polyvinyl alcohol (R-1130: manufactured by Kuraray Co.) 18.0% Polyoxyethylene tri bank sill ether (NOF) 1. 0% Sodium polyacrylate 1.5%

Table 1 shows the evaluation results of these recording sheets. For the recording characteristics of inkjet paper, the inkjet printer (BJ820J made by Canon) was used to measure the color density, and the color density was measured with a Macbeth densitometer for the printed matter. The line weight of the product was visually evaluated. The evaluation is indicated by ◯ for excellent performance, Δ for general quality, and x for defects having problems in use.

[0041]

[Table 1]

As is clear from Table 1, a coating layer containing a pigment and a water-based adhesive as main components was formed as an ink-receptive coating layer on at least one surface of a base paper containing cellulose pulp as the main component, The ink-receptive coating layer contains a spiro six-membered boric acid triester compound, and the coating amount is 2
When the content is in the range of 10 to 10 g / m ^2, the image by inkjet recording is clear, the printing density is uniform, and the resolution is satisfied (Examples 1 to 3), but the spiro 6-membered boric acid triester compound is used. Or the coating amount of the ink-receptive coating layer is less than ² g / m ² , the uniformity of concentration is lowered (Comparative Examples 1 and 2), and general surfactants cause large blurring. And the resolution is lowered (Comparative Example 3).

[0043]

EFFECTS OF THE INVENTION The ink jet paper of the present invention has clear printing, excellent ink absorption, and improved print density uniformity and resolution. It is possible to provide a high-resolution plain paper-like inkjet recording paper.

Claims (1)

[Claims] 1. A coating layer containing a pigment and a water-based adhesive as main components is formed as an ink receiving coating layer on at least one surface of a base paper containing cellulose pulp as a main component. Contains an spiro six-membered boric acid triester compound and has a coating amount of ² to 10 g / m ² .