JP2000301830A - Inkjet recording sheet - Google Patents

Abstract

(57) Abstract: An object of the present invention is to provide an ink jet recording sheet which is excellent in recording density, recording quality and water resistance of a recorded image, and is also excellent in light resistance of an image, especially a portrait image. An ink-jet recording sheet for forming a recorded image using an aqueous ink, wherein the recording sheet contains calcium propionate.

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 forming a recorded image using an aqueous ink, and more particularly to an ink jet recording sheet excellent in light resistance of a recorded image.

[0002]

2. Description of the Related Art Ink-jet recording is easy to achieve multi-color recording, has low noise, has a relatively high recording speed,
It has advantages such as being able to record on a large area, and is currently widely used in various fields such as various printers, facsimile machines and computer terminals, and is rapidly spreading. In the ink jet method using water-based ink, with the improvement of printer performance such as printing speed, resolution, gradation, etc., high-speed absorption of ink, high density, high image quality, Water resistance and also light resistance of images are required.

[0003] In order to respond to such demands, there have been many proposals regarding sheets provided with an ink receiving layer mainly composed of a pigment and an adhesive on a support. For example, a coating layer composed of amorphous silica and a polymer binder (JP-A-55-51583, JP-A-57-157786 and JP-A-62-158084), and a coating layer having an ink-adsorbing pigment such as zeolite ( JP-A-56-14417
No. 2), a coating layer composed of finely divided silicic acid and a water-soluble resin (JP-A-56-148583), and a coating layer having a porous cationic alumina hydrate (JP-A-60-2).
No. 32990) is provided on a support.

[0004] Among them, amorphous silica is a pigment most suitable for ink jet recording because it has a high ink absorption speed, a large ink absorption capacity, can print with high image quality, and does not impair the coloring of the dye. It is believed that. However, while the ink-receiving layer containing amorphous silica as a main component makes the coloring of the dye clear, it has the disadvantage that it promotes the decomposition of the dye by light and the recorded image is easily discolored or faded with time.

Further, from the viewpoint of improving the water resistance of printing, polycationic polymer electrolytes (JP-A-56-89992, JP-A-60-49990, and JP-A-61-125878).
Japanese Patent Application Laid-Open No. 57-36692), basic latex
Has been proposed in the ink receiving layer. However, although the use of such a water resistance improver improves the water resistance of the print, it causes a problem that photodecomposition of the dye is accelerated and light resistance is reduced.

A general method for improving the light fastness of an image is to improve the light fastness of the ink. However, the ink used for ink jet recording does not cause clogging of nozzles and has a vivid color tone. Since it is essential that the dye or pigment has heat resistance, it is not always possible to select a dye or pigment excellent in light resistance.

On the other hand, as a method for improving the light fastness of an image from the surface of an ink jet recording sheet, a metal oxide such as phosphotungstic acid, phosphomolybdic acid, chromic chloride, a metal chloride or tannic acid is used. A method of adding at least one (JP-A-57-87987), a method of adding an antioxidant such as a hindered phenol (JP-A-57-74192), and a method of adding a hindered amine (JP-A-57-74192) JP-A-61-146591), a method of adding an ultraviolet absorber such as a benzophenone-based, benzotriazole-based, or phenylsalicylic acid-based (Japanese Patent Laid-Open Nos. 57-74193, 57-87988, and 63-222885). ) Have been proposed, but none of them have been able to provide satisfactory effects.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet recording sheet which is excellent in recording density, recording quality and water resistance of recorded images, and which is excellent in light resistance of images, especially portrait images. It is in.

[0009]

According to the present invention, there is provided an ink jet recording sheet for forming a recorded image using an aqueous ink, characterized in that the sheet contains calcium propionate. It is.

According to the present invention, there is provided an ink jet recording sheet for forming a recorded image using an aqueous ink, wherein the sheet further contains at least one compound represented by the general formula (1) in addition to calcium propionate. It is an ink jet recording sheet characterized by containing.

[0011]

Embedded image

Wherein R ₂ represents a hydrogen atom or a methyl group, and X ⁻ represents an organic or inorganic anion. n shows 0 or the integer of 1-10. The present invention relates to an ink jet recording sheet in which a sheet has an ink receiving layer and calcium propionate is contained in the ink receiving layer. The present invention relates to an ink jet recording sheet having an ink receiving layer, wherein the ink receiving layer further contains at least one compound represented by the general formula (1) in addition to calcium propionate. Get involved.

According to the present invention, the ink receiving layer has a multilayer structure of two or more layers, the surface layer contains calcium propionate, and at least one of the layers other than the surface layer is represented by the general formula (1). The present invention relates to an ink jet recording sheet containing at least one compound of the formula (I).

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have found that an ink-jet recording sheet for forming a recorded image using an aqueous ink contains calcium propionate, whereby the image quality and the water resistance of the image are improved. In particular, they have found that an ink jet recording sheet with less discoloration of a portrait image due to light can be obtained, and have completed the present invention.

Although the reason why the light fastness of the portrait image is greatly improved is not clear, it is presumed that calcium propionate works well as a calcium source to stabilize the dye by chelation, thereby improving the light fastness. You.

The content of calcium propionate in the ink jet recording sheet is 0.1 to 4 g / m ^2.
Degree, preferably about 0.2 to ² g / m ² . Incidentally, if the amount is less than 0.1 g / m ² , the effect of improving light resistance becomes insufficient, and if it is more than 4 g / m ² , the image quality deteriorates, which is not preferable.

In the present invention, further, in the sheet,
By containing at least one of the compounds represented by the general formula (1), an ink jet recording sheet having improved light fastness synergistically was obtained.

[0018]

Embedded image

[Wherein, R ₂ represents a hydrogen atom or a methyl group, and X ⁻ represents an organic or inorganic anion. n shows 0 or the integer of 1-10. In the general formula (1), X ⁻ represents an organic or inorganic anion, and specific examples thereof include, for example, chloride ion, bromine ion, iodine ion, phosphate ion, pyrophosphate ion,
Metaphosphate ion, acetate ion, sulfate ion, nitrate ion, benzoate ion, p-toluenesulfonic acid ion,
Oxalate ion, tartrate ion, sulfosalicylic acid ion and the like can be mentioned.

When X ^- is a hydrogen atom in the general formula (1), an ink jet recording sheet having more excellent light resistance can be obtained.

Further, the compound represented by the formula (1) represented by n = 1 to 10, especially the compound represented by n = 1 to 3, has n = 0
In comparison with the compound represented by the formula (1), a more excellent effect is exhibited in terms of ink absorbability. When n exceeds 10, the compound (1) is localized in the recording sheet, and the effect of light resistance tends to decrease.

The content of the compound represented by the general formula (1) in the ink jet recording sheet is 0.1 to 4 g.
/ M ² , preferably about 0.2 to ² g / m ² . Incidentally, if the amount is less than 0.1 g / m ² , the effect of improving light resistance becomes insufficient, and if it is more than 4 g / m ² , the image quality deteriorates, which is not preferable.

In the ink-jet recording sheet, general phenol-based, thioether-based, phosphorus-based antioxidants, benzotriazole-based and benzophenone-based ultraviolet absorbers can be used as long as the effects of the present invention are not impaired. ,
It is also possible to add a singlet oxygen quencher or the like.

As a method for preparing an ink jet recording sheet, for example, a method of applying or impregnating a base paper with a coating liquid containing a specific compound by a size press or the like in a paper making process, an ink absorbing pigment, an adhesive, a specific compound, Further, if necessary, the coating liquid for the ink receiving layer obtained by mixing the cationic polymer is applied to a support such as high quality paper (acid paper, neutral paper), synthetic paper, film, non-woven fabric using a coating machine. Coating and drying to form an ink receiving layer, pigment, adhesive,
Further, a method of applying a coating liquid containing a specific compound on the ink receiving layer made of a cationic polymer, if necessary, may be mentioned. Above all, the method of including the specific compound in the ink receiving layer is preferable because the effect is improved by improving the light fastness of the image without deteriorating other qualities.

When the compound represented by the general formula (1) is used in combination, two or more ink receiving layers are provided, and calcium propionate is provided on at least the surface layer and at least one layer excluding the surface layer has the general formula ( The method of containing the compound represented by 1) is particularly preferable because it does not adversely affect the image quality and can obtain excellent light fastness.

Examples of the pigment to be contained in the ink receiving layer include zeolite, light calcium carbonate, heavy calcium carbonate, magnesium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium oxide, zinc oxide,
Zinc sulfide, zinc carbonate, satin white, aluminum silicate, diatomaceous earth, calcium silicate, magnesium silicate, amorphous silica, aluminum hydroxide, alumina,
Examples include alumina hydrate, lithopone, and urea-formalin resin filler. These may be used alone or in combination of two or more. Among these, amorphous silica,
Alumina and alumina hydrates, especially amorphous silica, are preferably used because of their excellent ink absorbency.

The amount of the pigment used in the ink receiving layer is as follows:
About 20 to 90% by weight based on the solid content of the ink receiving layer,
Preferably, it is about 30 to 80% by weight. If the content exceeds 90% by weight, the coating strength of the ink receiving layer decreases, and if the content is less than 20% by weight, the ink absorbency decreases, the ink drying property after recording becomes insufficient, and the image quality may deteriorate. is there.

In the present invention, a cationic polymer can be used for the purpose of improving the water resistance of a recorded image. Such a cationic polymer can be used as long as it dissociates when dissolved or emulsified in water to exhibit a cationic property. Among them, a polymer having a quaternary ammonium group in the main chain or side chain is preferable. Examples of such cationic polymers include dimethyldiallylammonium salt polymer, epichlorohydrin / dimethylamine polymer, polyamide polyamine epichlorohydrin polymer, ethyleneiminate polymer, and polyethyleneimine quaternary ammonium salt polymer. Product, acrylamide / diallyldimethylammonium chloride copolymer, (di) alkylaminoalkyl (meth) acrylate polymer, (meth) acryloyloxyalkyltrialkylammonium salt polymer, (meth) acrylamidoalkyltrialkylammonium salt polymer Products, (meth) acrylic (di) alkylaminoalkylamido acid salt polymer, polyalkylene polyamine dicyandiamide ammonium salt condensate, and the like. These may be used alone or in combination of two or more.

The content of the cationic polymer is usually 0.1.
It is adjusted in the range of 1 to 5 g / m ^2, preferably 0.2 to 3 g / m ² .

In the ink receiving layer, adhesives such as starch derivatives such as oxidized starch and etherified starch, cellulose derivatives such as carboxymethylcellulose and hydroxyethylcellulose, casein, gelatin, soy protein,
Complete (partial) saponified polyvinyl alcohol, silicon-modified polyvinyl alcohol, acetoacetyl group-modified polyvinyl alcohol, styrene-maleic anhydride copolymer salt, styrene-butadiene latex, acrylic latex, polyester polyurethane latex, vinyl acetate An aqueous adhesive such as latex or an organic solvent-soluble resin such as polymethyl methacrylate, a polyurethane resin, an unsaturated polyester resin, a vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, and an alkyd resin is used alone or in combination of two or more.

These adhesives are generally used in an amount of about 3 to 120 parts by weight, preferably 5 to 50 parts by weight, per 100 parts by weight of the pigment.
Used in the range of about parts by weight.

Further, in the ink receiving layer, a pigment dispersant,
Thickeners, crosslinkers, fluidity modifiers, defoamers, defoamers, release agents, foaming agents, penetrants, coloring dyes, coloring pigments, fluorescent brighteners, preservatives, anti-foaming agents, waterproofing Agents and the like can be appropriately added.

The ink receiving layer is prepared by applying a coating solution for the ink receiving layer to a bar coater, blade coater, air knife coater, or the like.
It is formed by applying and drying a coating method such as a gravure coater, a die coater, and a curtain coater on at least one surface of the support so that the coated amount after drying is about ² to 30 g / m ² . Incidentally, if the coating amount is less than 2 g / m ² , the recorded image quality is reduced, and if it is more than 30 g / m ² , the strength of the coating film may be reduced.

After the ink receiving layer is formed, it is of course possible to impart a smooth surface through the roll nip under pressure by using, for example, a super calender or a gloss calender.

The aqueous ink for forming a recorded image is a recording liquid comprising a colorant, a liquid medium, and other additives. Examples of the coloring agent include various water-soluble dyes such as direct dyes, acid dyes, and reactive dyes. As the liquid medium of the aqueous ink, there is water alone or a combination of water and a water-soluble organic solvent. Examples of the water-soluble organic solvent include monohydric alcohols such as ethyl alcohol and isopropyl alcohol, polyhydric alcohols such as ethylene glycol, diethylene glycol, polyethylene glycol and glycerin, and polyhydric alcohols such as triethylene glycol monomethyl ether and triethylene glycol monoethyl ether. And lower alkyl ethers of alcohols.
Further, examples of the additives include a pH adjuster, a metal sequestering agent, an anticorrosive, a viscosity adjuster, a surface tension adjuster, a surfactant, and a rust inhibitor.

[0036]

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. In the examples, "parts" and "%" indicate parts by weight and% by weight, respectively, unless otherwise specified.

Example 1 (Preparation of coating liquid A for ink receiving layer) 100 parts of synthetic amorphous silica (trade name: Fine Seal X45, manufactured by Tokuyama Soda)
150 parts of 20% silicon-modified polyvinyl alcohol aqueous solution (trade name: R1130, manufactured by Kuraray), 40 parts of 25% cationic polymer aqueous solution (trade name: PAS-J-81, manufactured by Nitto Bo) and 60 parts of 10% calcium propionate aqueous solution A coating liquid A for an ink receiving layer having a solid content concentration of 15%, comprising a small amount of an antifoaming agent, a dispersant and water.

(Preparation of Inkjet Recording Sheet) 6
After coating the ink receiving layer coating liquid A on a 5 g / m ² high quality paper with a wire bar so as to have a solid content of 12 g / m ² and drying to provide an ink receiving layer, a super calender treatment is performed to perform ink jet printing. A recording sheet was created.

Example 2 (Preparation of coating liquid B for ink receiving layer) 100 parts of synthetic amorphous silica (trade name: Fine Seal X45, manufactured by Tokuyama Soda)
150 parts of a 20% silicon-modified polyvinyl alcohol aqueous solution (trade name: R1130, manufactured by Kuraray), 20 parts of a 25% cationic polymer aqueous solution (trade name: PAS-J-81, manufactured by Nitto Bo) and 150 parts of a 10% aqueous solution of calcium propionate Thus, a coating liquid B for an ink receiving layer having a solid concentration of 15%, comprising a small amount of an antifoaming agent, a dispersant and water was obtained.

(Preparation of Coating Solution C for Ink Receiving Layer) 100 parts of synthetic amorphous silica (trade name: Fine Seal X45, manufactured by Tokuyama Soda), 20% silicon-modified polyvinyl alcohol aqueous solution (trade name: R1130, manufactured by Kuraray) 150 copies, 2
5% cationic polymer aqueous solution (trade name: PAS-J-
81, manufactured by Nitto Bo Co., Ltd. to obtain a coating liquid C for an ink receiving layer having a solid content of 15%, comprising 40 parts of a small amount of an antifoaming agent, a dispersant and water.

(Preparation of Inkjet Recording Sheet) 6
After providing the first ink-receiving layer by coating and drying a wire bar such that the 10 g / m ² coating liquid C for the ink receiving layer in solid content quality paper of 5 g / m ^2, further, the ink-receiving layer The coating liquid B was applied and dried with a wire bar so that the solid content was 5 g / m ^2, and the second ink receiving layer was provided. Then, a super calender treatment was performed to prepare an ink jet recording sheet.

Example 3 (Preparation of coating liquid D for ink receiving layer) 100 parts of synthetic amorphous silica (trade name: Fine Seal X45, manufactured by Tokuyama Soda)
150 parts of a 20% aqueous solution of silicon-modified polyvinyl alcohol (trade name: R1130, manufactured by Kuraray), 20 parts of a 25% aqueous solution of cationic polymer (trade name: PAS-J-81, manufactured by Nitto Bo) and 10 parts of hydrochloride of the following compound 1 % Aqueous solution, a small amount of an antifoaming agent, a dispersant, and water to obtain an ink receiving layer coating liquid D having a solid content concentration of 15%.

(Preparation of Ink-Jet Recording Sheet) 6
The coating liquid D for an ink receiving layer was applied on a high quality paper of 5 g / m ^{2 by} a wire bar to a solid content of 10 g / m ² and dried to form a first ink receiving layer. The coating liquid B was applied and dried with a wire bar so that the solid content was 5 g / m ^2, and the second ink receiving layer was provided. Then, a super calender treatment was performed to prepare an ink jet recording sheet.

[0044]

Embedded image Compound 1 n = 1 to 3, average molecular weight about 1900

Examples 4 to 6 Ink jet recording sheets were prepared in the same manner as in Example 3, except that the following compound was used instead of the hydrochloride of Compound 1. Example 4: Phosphate of Compound 1 Example 5: Phosphate of Compound 2 Example 6: Phosphate of Compound 3

[0046]

Embedded image Compound 2

[0047]

Embedded image Compound 3 n = 1 to 3, average molecular weight about 2000

Example 7 (Preparation of coating solution E for ink receiving layer) 100 parts of synthetic amorphous silica (trade name: Fine Seal X45, manufactured by Tokuyama Soda)
150 parts of a 20% silicon-modified polyvinyl alcohol aqueous solution (trade name: R1130, manufactured by Kuraray), 25 parts of a 20% cationic polymer aqueous solution (trade name: PAS-J-81, manufactured by Nitto Bo), 10% aqueous solution of 10% calcium propionate 15
0 parts and 50 parts of a 10% aqueous solution of the phosphate salt of compound 1,
Solid content concentration 15 consisting of a small amount of defoamer, dispersant and water
% Of a coating liquid E for an ink receiving layer.

(Preparation of Coating Solution F for Ink Receiving Layer) 100 parts of synthetic amorphous silica (trade name: Fine Seal X45, manufactured by Tokuyama Soda), 20% silicon-modified polyvinyl alcohol aqueous solution (trade name: R1130, manufactured by Kuraray) 150 copies, 2
5% cationic polymer aqueous solution (trade name: PAS-J-
81, manufactured by Nitto Bo) and 40 parts of compound 1 phosphate
A coating liquid F for an ink receiving layer having a solid content concentration of 15%, comprising 50 parts of a 0% aqueous solution, a small amount of an antifoaming agent, a dispersant, and water was obtained.

(Preparation of Inkjet Recording Sheet) 6
After providing the first ink-receiving layer by coating and drying a wire bar such that the 10 g / m ² coating liquid F for the ink-receiving layer in solid content quality paper of 5 g / m ^2, further, the ink-receiving layer The coating liquid D for application was applied and dried with a wire bar so as to have a solid content of 5 g / m ² to provide a second ink receiving layer, and then subjected to a super calender treatment to prepare an ink jet recording sheet.

Comparative Example 1 An ink jet recording sheet was prepared in the same manner as in Example 1 except that calcium propionate was not used.

Comparative Example 2 An ink jet recording sheet was prepared in the same manner as in Example 1, except that calcium chloride was used instead of calcium propionate.

Comparative Example 3 An ink jet recording sheet was prepared in the same manner as in Example 3 except that calcium propionate was not used.

The ink jet recording sheets obtained in Examples and Comparative Examples were evaluated as follows, and the results are shown in Table 1.
It was shown to.

[Image quality] Using an inkjet printer (trade name: PM-700C, manufactured by Seiko Epson),
An ISO-400 image (“High-definition color digital standard image data ISO / JIS-SCID”, p13, image name: portrait, published by The Japan Planning Association) was printed. The obtained image was visually observed, and the image quality was evaluated.

：: excellent △: slightly inferior, but no practical problem ×: very poor, practical problem

[Light resistance of image] A weather meter (model name: SUNSHINE XENON LONG LIFE W) in which the obtained image was set under the conditions of light source: xenon, 63 ° C, 40% RH.
EATHERMETER, manufactured by Suga Test Machine Co., Ltd.) for 20 hours, and the level of light resistance was visually observed and evaluated.

A: Almost no discoloration was observed. Δ: Despite fading and fading, the color balance is not broken and there is almost no problem in practical use. ×: Fading / fading is remarkable and there is a practical problem.

[Image Water Resistance] One drop of water was dropped on the obtained image, and after 1 minute, it was wiped off and its water resistance was visually observed. ：: Discoloration and discoloration and bleeding are not observed at all. △: Discoloration and discoloration and bleeding are slightly observed, but there is no practical problem. X: Discoloration and discoloration and bleeding are remarkable.

[0060]

[Table 1]

[0061]

As is evident from Table 1, the ink jet recording sheet of the present invention has less discoloration and discoloration of an image, especially a portrait image, even when exposed to light for a long time, and has a high image quality and water resistance. Was also an excellent recording sheet.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H086 BA15 BA16 BA38 4D075 AE03 CA35 DA04 DB18 DC27 EA06 EC07 4L055 AG18 AG34 AG35 AG64 AG94 AH02 AH25 AH37 AJ04 BE09 FA11 GA09

Claims (5)

[Claims] 1. An ink jet recording sheet for forming a recorded image using an aqueous ink, characterized in that the recording sheet contains calcium propionate. 2. The ink jet recording sheet according to claim 1, wherein said recording sheet further contains at least one compound represented by the general formula (1). Embedded image [Wherein, R ₂ represents a hydrogen atom or a methyl group, and X ⁻ represents an organic or inorganic anion. n shows 0 or the integer of 1-10. ] 3. The ink jet recording sheet according to claim 1, wherein said recording sheet having an ink receiving layer contains calcium propionate in said ink receiving layer. 4. The ink jet recording sheet according to claim 3, wherein the ink receiving layer further contains at least one compound represented by the general formula (1). 5. The ink receiving layer has a multilayer structure of two or more layers, a surface layer containing calcium propionate, and at least one layer other than the surface layer has the general formula (1):
5. The ink jet recording sheet according to claim 4, wherein the sheet comprises at least one compound represented by the formula: