JP2002293000A - Ink jet recording sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording sheet having excellent ink absorbability and having a clear recording image and a high quality. SOLUTION: The ink jet recording sheet comprises an ink acceptive layer containing a white pigment, a cationic ink fixing agent as main components and provided on a sheet-like support. In this sheet, a specific acetyleneglycol derivative or a specific dialkylsulfosuccin alkali metal salt is coated on the acceptive layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording sheet used for an ink jet recording system using an aqueous ink.
More specifically, the present invention relates to an ink jet recording sheet from which a recorded image having excellent ink absorbability can be obtained.

[0002]

2. Description of the Related Art Ink-jet printer performance in recording using water-based ink, especially ink absorption and ink absorption for recording sheets due to the improvement of recording speed, resolution, saturation, etc. with rapid development of colorization. Advanced characteristics such as capacity and dot uniformity are required,
A so-called coated paper type ink jet recording sheet has been developed in which a white pigment is applied from a conventional plain paper type ink jet recording sheet to a sheet-like support such as paper to provide an ink receiving layer.

For example, Japanese Patent Application Laid-Open No. Sho 60-171190 discloses that a specific amount of a specific nonionic surfactant is added to a coating liquid composed of a white pigment and an adhesive so as to enhance the ink absorbency and to improve the hue and lightness. JP-A-60-19, excellent in chroma
No. 8285 has a surface containing a surfactant that does not insolubilize the dye on the surface and contains a compound that insolubilizes the dye in a layer close to the substrate, so that there is no white spots on the solid image. Japanese Patent Application Laid-Open No. 9-248958 discloses that a layer containing a water-soluble polymer compound and a surfactant is provided to eliminate fingerprint adhesion and stickiness under high humidity, and to provide excellent recording characteristics. It has been proposed that a coating liquid containing synthetic amorphous silica + polyvinyl alcohol + polyamide polyamine epichlorohydrin, and further containing a dialkyl sulfosuccinate ester salt, reduce image bleeding and powder dropping, and have excellent water resistance. I have.

In the follow-up experiments of the present inventors, there are proposals which are not practically sufficient, for example, the solid image has no white spots and the ink absorption can be improved, but the coating layer strength is reduced or the effect is small. In general, when a surfactant is added to a coating solution, the strength of the coating layer tends to decrease, and an increase in the amount of the adhesive decreases the ink absorbability, and is not a good measure.

[0005]

The decrease in the coating layer strength is caused by the coating layer powder adhering to the paper feed rubber roll of the color printer.
This leads to a decrease in transportability. In addition, the printing durability (blanket stain) during offset printing for business cards and postcards occurs.
Further, the decrease in ink absorbability causes ink overflow and bleeding particularly in a card printer having a high color recording speed, and is not practical. Therefore, an attempt is made to maintain the ink absorbency by increasing the coating amount, but there is a limit in balancing the strength of the coating layer and the ink absorbency, which is a major problem. Accordingly, an object of the present invention is to provide an ink jet recording sheet capable of obtaining an excellent high quality recorded image by improving the coating layer strength and the ink absorbency.

[0006]

As a result of extensive studies and experiments, the present inventor has found that, in an ink jet recording sheet having a sheet-like support provided with an ink receiving layer containing a white pigment as a main component, an ink receiving layer is provided. The present invention is based on the finding that the object can be achieved by coating the above with an acetylene glycol derivative represented by the following general formula (1) or an alkali metal salt of dialkyl sulfosuccinic acid represented by the following general formula (2). Reached.

[0007]

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In the general formula (1), R _{1 to} R _{4 each} have _{1 to 4} carbon atoms.
Represents an alkyl group. m + n = 3 to 30 moles of ethylene oxide added.

[0009]

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In the general formula (2), R ₅ and R _{6 each} have 4 to 1 carbon atoms.
2 represents an alkyl group. M represents an alkali metal salt such as lithium, sodium and potassium.

That is, by coating the acetylene glycol derivative or the alkali metal dialkyl sulfosuccinate of the present invention on the ink receiving layer, the strength of the coating layer is not reduced at all and the ink absorbency is greatly improved. Blurring of the recorded image by the printer is eliminated, and the sharpness is improved.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Examples of the acetylene glycol derivative represented by the above general formula (1) used in the present invention include the following.

[0013]

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[0014]

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[0015]

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[0016]

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[0017]

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As the alkali metal dialkylsulfosuccinate represented by the general formula (2) used in the present invention, a sodium salt is generally commercially available, and examples thereof include the following.

[0019]

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[0020]

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[0021]

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[0022]

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[0023]

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[0024]

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[0025]

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[0026]

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[0027]

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The acetylene glycol derivative represented by the general formula (1) and the alkali metal salt of dialkylsulfosuccinic acid represented by the general formula (2) used in the present invention are each formed into an aqueous solution, and are used in an air knife coater and a curtain coater. The coating amount on the ink receiving layer by a coating method such as a bar coater or a roll coater is 0.05 to ² g / m ² (dry weight solid content), particularly preferably 0.1 to 1 g / m ^2. Coating and drying to obtain an ink jet recording sheet. Although the ink receiving layer of the present invention has a highly smooth surface quality, it is preferable to perform treatment with a smoothing device such as a super calender or a soft calender in order to obtain a more excellent recorded image.

As the sheet-like support used in the present invention, an acid paper, a neutral paper, or the like for general coated paper is appropriately used. The sheet-like support is mainly composed of wood pulp, and a white pigment is added and mixed as needed. Wood pulp is various chemical pulp, mechanical pulp, recycled pulp, etc., and these pulp are beaten with a beater to maintain the suitability for ink-jet recording such as papermaking suitability, coating suitability, ink absorption and recording surface quality. Adjust the degree (freeness). The degree of beating of the pulp varies depending on the type of the pulp and is not particularly limited.
P-8121] is preferred. For the white pigment, talc, calcined kaolin, silica, calcium carbonate, titanium dioxide, and the like are appropriately mixed in order to adjust opacity, ink absorbency, and the like. The mixing ratio is 1 to 100 parts by weight of pulp.
It is 30 parts by weight, preferably 5 to 20 parts by weight.

A sizing agent, a paper strength enhancer, a retention enhancer, and the like are added as auxiliaries, and a water-soluble polymer such as starch is further applied and impregnated in a size press process of a paper machine to obtain surface strength, sizing degree, etc. To adjust. The basis weight of the sheet-like support to be formed is 40 to 350 g / m ² , and the size varies depending on the basis weight.
When the sizing degree is low, there is a problem in operation due to paper breakage or wrinkles at the time of coating, and when the sizing degree is high, the absorbability is poor and bleeding occurs.

Examples of the white pigment of the ink receiving layer used in the present invention include talc, kaolin, calcined kaolin, acid clay, activated clay, calcium carbonate, magnesium carbonate, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, sulfide. Zinc, zinc carbonate, satin white, aluminum silicate, calcium silicate, magnesium silicate, aluminum hydroxide, synthetic amorphous silica, colloidal silica, colloidal alumina, alumina, lithopone,
Inorganic white pigments such as zeolite and hydrohaloysite; plastic pigments such as polyethylene, polystyrene and polyacrylate; and organic white pigments such as urea resin and melamine resin. One type or a mixture of two or more types is used. Particularly preferred is synthetic amorphous silica. The dispersant for the synthetic amorphous silica used in the present invention includes sodium pyrophosphate, sodium hexametaphosphate, sodium tripolyphosphate, sodium polyacrylate, sodium hydroxide, sodium silicate, and the like, and preferably sodium polyacrylate. , Sodium hydroxide and sodium silicate.

In the present invention, an adhesive is contained in order to adhere the white pigment to the sheet-like support. Examples of the adhesive used in the present invention include natural or semi-synthetic water-soluble polymers such as starch, casein, soybean protein, gelatin, carboxymethylcellulose, and hydroxyethylcellulose; water-soluble polymers such as polyvinyl alcohol, silanol-modified polyvinyl alcohol and derivatives thereof. Water-soluble polymer; conjugated diene polymer latex such as styrene butadiene copolymer, methyl methacrylate butadiene copolymer, and vinyl polymer latex such as ethylene vinyl acetate copolymer; To use.

In the present invention, the ink receiving layer contains a cationic ink fixing agent in order to improve the weather resistance of the recorded image. Examples of the cationic ink fixing agent used in the present invention include a copolymer of dimethyldiallylammonium chloride and acrylamide, a polymer of alkyl (meth) acrylate or a quaternary ammonium compound of alkyl (meth) amide, or a quaternary polymer. 50 ammonium chloride
Mol% or more of copolymer, acrylamide / acrylonitrile / N-vinylacrylamidine hydrochloride / N-
Vinyl acrylamide / vinylamine hydrochloride / N-vinylformamide copolymer, dimethylamine / epichlorohydrin polycondensate, polyethylene polyamine / dimethylamine / epichlorohydrin polycondensate, acrylamide / diallylamine copolymer, etc. .

In the present invention, a fluorescent whitening agent and a dot adjusting agent are mixed in the ink receiving layer in order to improve the sharpness of the recorded image and obtain a high quality image. Examples of the optical brightener include pyrene derivatives, coumarin derivatives, aminocoumarin derivatives, carpostyryl derivatives, dibenzoxazolyl derivatives, thiazole derivatives, imidazole derivatives, benzimidazole derivatives, imidazoline derivatives, pyrazoline derivatives, benzidine derivatives, stilbene derivatives, Distilbene derivatives, disulphonic acid derivatives, naphthalimide derivatives, distyrylbiphenyl derivatives and the like can be mentioned. Particularly preferred are disulphonic acid derivatives, specifically fluorescent-85, fluorescen-86, fluorescen- 90,4,4'-bis [2-sodiumsulfanyl-4-di (hydroxyethyl) amino-1,3,5-
Triazinyl- (6) -amino] stilbene-2,2 '
-Sodium disulfonate.

Examples of the dot adjusting agent include a reinforced rosin sizing agent, a petroleum resin sizing agent, an emulsion sizing agent, a reactive sizing agent such as alkenyl succinic anhydride, a self-fixing cationic resin sizing agent, a wax emulsion, and silicones. Or various latexes used in adhesives. Further, in the present invention, if necessary, a preservative such as benzimidazolyl carbamic acid methyl ester and allyl methanol mono (poly) hemifomal is appropriately added to form a coating liquid for an ink receiving layer, and a blade coater, an air knife coater, a curtain coater, Bar coater,
An ink receiving layer is formed by coating and drying the sheet-like support with a coating method such as a gravure coater or a roll coater so that the coating amount is 3 to 30 g / m ² (dry weight solid content).

The support of the ink jet recording sheet of the present invention is preferably paper, but is not limited thereto.
In addition to paper, a synthetic resin-coated paper in which both surfaces of a sheet-like support are coated with a polyolefin-based resin, or a film-like support may be used. Further, a pressure-sensitive adhesive layer or a label adhesive layer can be provided on the back surface of the ink jet recording sheet of the present invention.

[0037]

The preferred embodiments of the present invention and the excellent effects thereof will be specifically described below with reference to the most typical examples. In the following, all parts are parts by weight, and all percentages are by weight.
It is.

[Preparation of Support] LBKP (CSF 350 ml) 100 parts Talc 20 parts Rosin size emulsion 1.5 parts Sulfuric acid band 5 parts Amphoteric starch 2 parts

After forming a 1% slurry of the above composition,
Pressing is performed with an aqueous% oxidized starch (manufactured by Nippon Shokuhin Kako Co., Ltd .: MS-3800) aqueous solution so as to have a coating weight of 0.5 g / m ² (dry weight solid content) on both sides to obtain a support having a basis weight of 165 g / m ² Was.

[Preparation of Ink Receiving Layer] Aqueous solution of 40% sodium polyacrylate aqueous solution (manufactured by Toagosei Chemical Industry Co., Ltd .: T-40) 1.5 parts Amorphous synthetic silica powder (manufactured by Tokuyama: Fine Seal X37B, average particle size 3) 7 parts) 70 parts Amorphous synthetic silica powder (manufactured by Tokuyama: Fine Seal X60, average particle diameter 6.0 μm) 10 parts Amorphous synthetic silica powder (manufactured by Mizusawa Chemical Industries: Mizukasil P78D, average particle diameter 7.5 μm) 20 parts Silica dispersion water 454 parts 25% fluorescen-85 aqueous solution 8 parts 10% polyvinyl alcohol aqueous solution (manufactured by Kuraray: PVA117, polymerization degree 1700, saponification degree 98.5 mol%) 300 parts acrylamide / acrylonitrile / N- Vinylacrylamidine hydrochloride / N- vinylacrylamide / vinylamine hydrochloride / N-vinyl 30% aqueous solution of 70 parts of 55% ethylene-vinyl acetate copolymer emulsion of formamide copolymer (manufactured by Sumitomo Chemical Co., Ltd.: Sumikafu Rex S400) 18 parts

The above composition was used as a coating liquid for an ink receiving layer.
Next, the basis weight of 165 g / m obtained above ^TwoThe coating on the support of
The coating amount of the liquid is 7.5 g / m with an air knife coater.
^Two(Dry weight solids)
Thus, a black receiving layer was obtained.

Example 1 A 1% aqueous solution of the compound of the formula (5) (m + n = number of moles of ethylene oxide added: 10 mol) was prepared. Next, the aqueous solution was coated on the ink receiving layer obtained above with an air knife coater so as to have a coating amount of 0.5 g / m ² (dry weight solid content), and then subjected to a super calender treatment to obtain an inkjet. A recording sheet was obtained.

Example 2 A 1% aqueous solution of the compound of the above formula (m + n = the number of moles of ethylene oxide added: 10 mol) was prepared. Next, the aqueous solution was coated on the ink receiving layer obtained above with an air knife coater so as to have a coating amount of 0.5 g / m ² (dry weight solid content), and then subjected to a super calender treatment to obtain an inkjet. A recording sheet was obtained.

Example 3 A 1% aqueous solution of the compound of the above formula (m + n = 3 moles of ethylene oxide added) was prepared. Next, the aqueous solution was applied onto the ink receiving layer obtained above using an air knife coater so that the coating amount was 0.5 g / m ² (dry weight solid content).
After drying, a super calendar treatment was performed to obtain an ink jet recording sheet.

Example 4 A 1% aqueous solution of the compound of the above formula (m + n = the number of moles of ethylene oxide added: 30 mol) was prepared. Next, the aqueous solution was coated and dried on the ink receiving layer obtained above using an air knife coater so as to have a coating amount of 0.5 g / m ² (dry weight solid content), and then subjected to a super calendering treatment and ink jet printing. A recording sheet was obtained.

Example 5 A 1% aqueous solution of the compound of the above formula (10) was prepared. Next, the aqueous solution was coated on the ink receiving layer obtained above with an air knife coater so as to have a coating amount of 0.5 g / m ² (dry weight solid content), and then subjected to a super calender treatment to obtain an inkjet. A recording sheet was obtained.

Example 6 A 1% aqueous solution of the compound of formula 14 was used. Next, the aqueous solution was coated on the ink receiving layer obtained above with an air knife coater so as to have a coating amount of 0.5 g / m ² (dry weight solid content), and then subjected to a super calender treatment to obtain an inkjet. A recording sheet was obtained.

Example 7 A 1% aqueous solution of the compound of the above formula 18 was prepared. Next, the aqueous solution was coated on the ink receiving layer obtained above with an air knife coater so as to have a coating amount of 0.5 g / m ² (dry weight solid content), and then subjected to a super calender treatment to obtain an inkjet. A recording sheet was obtained.

Comparative Example 1 The sheet provided with the ink receiving layer obtained above was subjected to a super calender treatment to obtain an ink jet recording sheet.

Comparative Example 2 Water was applied on the ink receiving layer obtained above with an air knife coater and dried, and then subjected to a super calender treatment to obtain an ink jet recording sheet.

Comparative Example 3 A 1% aqueous solution of polyethylene glycol (# 200) was used. Next, the aqueous solution was coated on the ink receiving layer obtained above with an air knife coater so as to have a coating amount of 0.5 g / m ² (dry weight solid content), and then subjected to a super calender treatment to obtain an inkjet. A recording sheet was obtained.

The ink jet recording sheets obtained in Examples 1 to 7 and Comparative Examples 1 to 3 were measured and evaluated by the following methods.

Evaluation method << Coating strength of ink receiving layer >> Coating when accelerated printing was performed with a RI tester (manufactured by Ishikawajima Sangyo Kikai: AKIRA) using black ink (manufactured by Dainippon Ink: Ink Black, TV25). Layer peeling was visually determined.印: No peeling of the coating layer on the surface of the ink receiving layer. << Printing Durability >> Indigo Ink (Dainippon Ink: GEOS-G
Printing machine (Mitsubishi Heavy Industries: Diamond 3H-4)
And blanket stains at the time of offset printing were visually determined.印: no coating layer, paper powder, etc. adhered to the blanket.

<< Ink Absorption >> 100% cyan + magenta 1 by a card printer (Canon P400CII)
The number of seconds required for the ink printed with the 00% heavy-color solid print to penetrate into the ink receiving layer and become apparently dry was measured.印: Dry state almost simultaneously with printing. X: It takes 10 seconds or more until it becomes a dried state after printing, which is not practical. << Print Density >> Card Printer (Canon P400CI
The optical density of the solid black image printed in I) was measured with a Macbeth densitometer RD918. The larger the value, the higher the concentration and the better.

<< Bleeding of Printed Image >> The bleeding evaluation pattern printed by a card printer (Canon P400CII) was visually judged.印: very good without any bleeding X: Bleeding is not practical.

Table 1 summarizes the above evaluation results. The comprehensive evaluation means the following.印: Practically very good. X: Not practical.

[0057]

[Table 1]

[0058]

As is clear from the above examples, according to the present invention, the coating layer strength is not reduced at all, the ink absorbency is greatly improved, and especially the bleeding of the recorded image in a card printer is eliminated. The sharpness was improved.

Claims (2)

[Claims] 1. An ink jet recording sheet having a sheet-like support provided with an ink receiving layer containing a white pigment as a main component, wherein an acetylene glycol derivative represented by the following general formula (1) is coated on the ink receiving layer. An ink jet recording sheet comprising: Embedded image [In the general formula (1), R _{1 to} R ₄ represent an alkyl group having 1 to ₄ carbon atoms. m + n = 3 to 3 moles of ethylene oxide added
Represents 0. ] 2. In an ink jet recording sheet having a sheet-like support provided with an ink receiving layer containing a white pigment as a main component, an alkali metal salt of a dialkyl sulfosuccinic acid represented by the following general formula (2) is formed on the ink receiving layer. An ink jet recording sheet characterized by being coated. Embedded image [In the general formula (2), R ₅ and R ₆ represent an alkyl group having 4 to 12 carbon atoms. M represents an alkali metal salt. ]