JP3195330B2 - Method of manufacturing ink jet recording paper and ink jet recording paper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention is, the ink-jet Symbol
The present invention relates to a recording sheet manufacturing method and an ink jet recording sheet.

[0002]

2. Description of the Related Art The ink jet recording system has been used because it has an advantage that a full color printing is easy and noise during recording is small. For this purpose, there are demands for ink jet recording paper, such as excellent ink absorption without bleeding, excellent smoothness and gloss of the paper surface, high print density, and high print water resistance. In general, ink jet recording paper is prepared by coating a base paper with a coating liquid containing a pigment and a binder as main components, such as a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a rod blade coater, a lip coater, a curtain coater, and a die coater. It can be obtained by coating using the above.

As the pigment used here, amorphous silica or synthetic silica, clay, calcium carbonate and the like are used. It is preferable to use silica having a large specific surface area in that the ink absorbency is increased.

[0004]

However, conventional ink jet recording papers do not always have sufficient ink absorbency and are not satisfactory in preventing bleeding. Thus, the present inventors have found that, when a special light calcium carbonate is used as a pigment, it shows excellent ink absorbency, enables clear printing with almost no bleeding, and is extremely resistant to fading resistance and yellowing of paper. I found that it was excellent.

Accordingly, it is a main object of the present invention to provide an ink having excellent ink absorbency, capable of sharply printing with almost no bleeding, being extremely excellent in fading resistance and yellowing of paper, and having smoothness of recording paper surface. An object of the present invention is to provide a method for producing an ink jet recording sheet and an ink jet recording sheet which are excellent in glossiness and can reduce the cost as compared with the case where silica is used as a pigment.

[0006]

The present invention which has solved the above-mentioned problems is as follows.

<Invention of Claim 1> At least one surface of the base paper has a specific surface area of 50 to 130.
A coating layer containing 50 to 50 parts by weight of a light calcium carbonate of m ² / g in the pigment and 100 to 100 parts by weight of the pigment is formed.
Apply the moistened coating layer to the mirror-finished and heated cylindrical outer surface.
By the cast coating method of pressing against the drum
A method for producing an ink jet recording paper , comprising forming a receiving layer .

(Function and Effect) A. The specific surface area of general light calcium carbonate is 0.5 m ²
/ G to 10 m ² / g. However, the light calcium carbonate used in the present invention has a specific surface area of 50 to 130.
It is extremely high at m ² / g. As a result, since many microscopic holes are formed in the coating layer of the recording paper, when ink is received, the pigment in the ink is left in many microscopic holes on the surface of the coating layer, Only the water in the ink passes through the holes, passes through the coating layer, and penetrates into the base paper. Therefore,
It has excellent ink absorbency and prevents bleeding due to diffusion of water. In order to sufficiently exhibit this effect, it is preferable that light calcium carbonate is contained in the pigment in an amount of 50% by weight or more, desirably 70% by weight or more, particularly 90% by weight or more. B. Since the light calcium carbonate of the present invention is excellent in binding properties, with respect to the risk of powder dropping, the binder is used in an amount of 5 to 50 parts by weight, preferably 10 to 30 parts by weight, based on 100 parts by weight of the pigment.

<Invention according to claim 3> At least one surface of the base paper has a specific surface area of 50 in the pigment.
The pigment 100 contains at least 50% by weight of light calcium carbonate having a weight of about 130 m ² / g, less than 50% by weight of synthetic silica, and a cationic compound of an aluminum compound.
An ink jet recording sheet comprising a receiving layer containing 5 to 50 parts by weight of a binder with respect to parts by weight.

(Function and Effect) In the present invention, the following advantages are provided in addition to the above-mentioned A and B. C. In the present invention, an aluminum compound cationic agent is contained. The reason for this addition is that, compared to other polymer-based cation agents, the aluminum compound cation agent is extremely excellent in improving the fixability and water resistance of the ink. The content ratio of the aluminum compound cation agent is preferably 0.1 to 8% by weight based on the binder. D. Synthetic silica, desirably having a specific surface area of 150 m ² / g
By containing less than 50% by weight of the above synthetic silica,
The ink absorbency can be further improved. In the pigment,
More preferably, 70 to 95% by weight of light calcium carbonate having a specific surface area of 50 to 130 m ² / g and 5 to 30% by weight of synthetic silica are contained.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the pigment has a specific surface area of 50 to 130 m ² / g, more preferably 70 to 9 m ² / g.
Use 0 m ² / g light calcium carbonate. In the present invention, it is necessary to include a pigment in the coating layer and to use the light calcium carbonate as a pigment in the pigment in an amount of 50% by weight or more. 90% by weight to improve the absorption of
It is preferable to use the above.

As the content of the light calcium carbonate is increased, the dot density is increased, the sharpness is improved, and the roundness is improved. In this case, an excellent recorded image can be obtained. But 70% by weight
If the content is less than the above range, the density of the dots may be insufficient and the color reproducibility from the original may be poor.

In the present invention, the pigment which can be used in combination with the above-mentioned light calcium carbonate is preferably synthetic silica. When synthetic silica, especially synthetic silica having a specific surface area of 150 m ² / g or more, is used, the ink absorbency can be improved. However, other pigments can also be used, and pigments used for ordinary paper coating can be appropriately selected and used.

Examples of the pigment include inorganic pigments such as kaolin, clay, talc, ordinary light calcium carbonate, heavy calcium carbonate, aluminum hydroxide, titanium dioxide, and satin white; and organic pigments such as plastic pigment. Can be. When an organic pigment is used, its content is preferably set to 6% by weight or less in the pigment. The pigment can be easily contained in the coating layer by mixing and dispersing the pigment in a coating liquid by a known method.

In the present invention, a binder is added to the coating liquid in order to impart the binding property to the base paper to the pigment and form a uniform coating layer. Examples of the binder include oxidized starch, starches such as esterified starch, carboxymethylcellulose, cellulose derivatives such as hydroxyethylcellulose, polyvinyl alcohol and derivatives thereof, casein, gelatin, soy protein, styrene maleic acid resin and derivatives thereof, Conjugated diene polymer latex such as styrene-butadiene copolymer, methyl methacrylate-butadiene copolymer, acrylic polymer latex such as acrylate and methacrylate polymer or copolymer, ethylene vinyl acetate copolymer Examples thereof include a vinyl polymer latex such as a coalescence, a vinyl acetate emulsion, and a condensate of two or more of these. The amount of binder used is pigment 100
5 to 50 parts by weight, more preferably 20 to 3 parts by weight based on parts by weight
0 parts by weight. In addition, the coating liquid, if necessary, a pigment dispersant, a water retention agent, a thickener, a defoamer, a release agent, a preservative,
Color pigments, water-proofing agents, wetting agents, fluorescent dyes, ultraviolet absorbers and the like can be added.

In the present invention, it is preferable that the coating layer contains a cationic polymer in order to improve the water resistance of the recorded image. Such a cationic polymer electrolyte reacts with a water-soluble direct pigment in an ink to be used or a —SO ₄ Na group, a —SO ₄ H group, a —NH ₄ group, or the like in an acid dye molecule to be insoluble in water. This prevents the dye in the ink from dissolving in water and improves the water resistance of the recorded image.

The above-mentioned cationic polymer electrolyte includes:
For example, polyvinylbenzyltrimethylammonium halide, polydiacryldimethylammonium halide, polydimethylaminoethyl methacrylate hydrochloride, polyethyleneimine, dicyandiamide formalin condensate, epichlorohydrin-modified polyalkylamine,
Examples thereof include polyvinyl pyridinium halide, polyethyleneimine quaternary ammonium salts, and polyamine.

The coating amount is 0.5 to 50 as a dry film thickness.
μm. The base paper used in the present invention is not particularly limited, and may be appropriately selected from known papers such as neutral paper mainly made of wood pulp, which is generally used for ink jet recording paper.

In the present invention, when forming the receiving layer,
-Wet coating without using a
The layer is mirror-finished and heated with a cylindrical outer surface.
Adopt a cast coating method that presses against the

On the other hand, when synthetic silica is used as a pigment, it is desirable to include an aluminum compound cationizing agent in the coating liquid in order to adjust the viscosity and obtain a high image density. As the aluminum compound cation agent,
Organoaluminum compounds, inorganic salts of aluminum, aluminum oxides, aluminum hydroxide, etc., or the pigments exemplified above, which have been treated such that the above compounds are electrically or otherwise adsorbed on the surface or reacted with hydroxyl groups on the surface. Can be used.

The organoaluminum compound may be any of the conventionally known organoaluminum compounds, but preferred are aluminum compounds such as aluminum alcoholate compounds, aluminum chelate compounds and cyclic aluminum oligomers. It has reactivity with the adsorbing component and the surface functional group existing on the surface. Preferred specific examples of the organoaluminum compound include, for example, aluminum ethylate,
Aluminum isopropylate, monosec-butoxyaluminum diisopropylate, aluminum sec
Aluminum alcoholate compounds such as butyrate; ethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate),
Aluminum chelate compounds such as alkyl acetoacetate aluminum diisopropylate, aluminum monoacetylacetonate bis (ethylacetoacetate) aluminum tris (acetylacetonate); and cyclic aluminum oligomers such as cyclic aluminum oxide isopropylate and cyclic aluminum oxide stearate. No. Alternatively, aluminum stearate or laurate may be used. Aluminum inorganic salts include chlorides, sulfates, nitrates, ammonium salts, acetates, carbonates, nitrates, etc., as well as aluminates such as sodium aluminate and potassium aluminate, and salts such as alum. Which may also have water of crystallization.

Calcination of aluminum oxide, aluminum hydroxide obtained by baking bauxite, which is industrially a natural mineral, with thermoplastic soda or metal aluminum pellets by spark discharge in pure water. The production method itself is conventionally known, and various crystal systems (α-form, γ-form, δ-form, η-form, θ-form,
) And those having various particle diameters, high densities and specific surface areas are commercially available, and the present invention includes all of these aluminas.

[0023]

EXAMPLES (Example 1) 370 ml of freeness (CSF) as raw pulp
LBKP 85 parts (hereinafter, “parts” means parts by weight,
"%" Means% by weight. ), Freeness (C.I.
S. F) 440 ml of NBKP 15 parts were mixed and obtained.
The basis weight 80 g / m ² base paper, coating the following coating solution so that the coating amount 10 g / m ² by an air knife coater,
Immediately, the wet coated layer was mirror-finished and pressed against a drum having a cylindrical outer surface heated to 80 ° C. to form a receiving layer by a wet cast coating method in which the paper surface was glossy.

As the coating liquid , light pigments such as
Cium (BET specific surface area 80m ² / g, trade name: JET
30), polyvinyl alcohol as a binder
( R-1130: manufactured by Kuraray Co., Ltd., solid content concentration 10%),
Cationic dye fixing agent (Sumireze resin 1001: Sumitomo
Manufactured by Tomo Chemical Co., Ltd., solid content concentration 30%)
Cetacetate aluminum diisopropylate (Al
MICHERATE M: manufactured by Kawaken Fine Chemicals Co., Inc.
Was used in the formulation of Table 1.

(Other Examples and Comparative Examples ) Synthetic amorphous silica (Mizukasil P-78A: Mizusawa Chemical Co., Ltd.)
), Light calcium carbonate, synthetic non-
Change the amount of crystalline silica, binder, and cationic agent
A further coating solution was used. In addition , the specific surface area as a pigment
Various examples of ink jet recording paper were obtained using other light calcium carbonate (TP-121, manufactured by Okutama Kogyo Co., Ltd.) which was not 50 to 130 m ² / g . In addition, aluminized
The case where alkyl acetoacetate aluminum diisopropylate as a compound cation agent was not added was also examined. In addition, super-calendered products were also examined.

<Evaluation Method> The recording densities, ink absorbency, glossiness, and bleeding of the ink jet recording papers obtained in Examples and Comparative Examples were evaluated by the following methods. Table 1 shows the results.

[0027]

[Table 1]

[Recording Density] Solid recording of four colors (black, cyan, magenta, yellow) using a Canon full color printer BJF600 at a temperature of 20 ° C. and a humidity of 20% (size: 3.0 cm × 3.0 cm) The recording density was measured with a Macbeth densitometer (RD915) in a state where the ink penetration was stable 30 minutes after printing. The table shows the total of the measured values of the four colors, and 3.3 or more was regarded as good. [Ink Absorbency] Print each single color of yellow, magenta, and cyan, attach a high quality paper to the printed surface printed every 5 seconds immediately after printing, and observe whether the ink is transferred to the high quality paper. (○: less than 10 seconds, Δ: 10 to 30 seconds, ×: 3
(0 second or more) When the time until the ink dries is less than 10 seconds, the ink absorbency is excellent. [Glossiness of print portion (shininess)] The glossiness of the print portion was visually observed from a lateral angle of 20 ° with respect to the print portion, and evaluated in four steps as follows. ：: There is the same level of shine as a silver halide color photograph. ：: Inferior to color photograph, but with high shine. Δ: comparable to coated paper print product. X: comparable to general PPC. "Bleeding" Using a Canon full color printer BJF600 at a temperature of 20 ° C. and a humidity of 20%, solid recording of red, green, and purple alternately made of three primary colors (cyan, magenta, and yellow inks), respectively ( Size 3.0c
m × 3.0 cm) was continuously recorded, and the degree of occurrence of bleeding on adjacent ink jet inks or on one side was evaluated in a state where ink penetration was stable after 30 minutes from printing. Evaluation A- No bleeding of ink. Evaluation B-Slight bleeding of the ink was observed. Evaluation C- There is a clear bleeding of the ink.

<Consideration> (Comparison between use of light calcium carbonate having a specific surface area of 50 to 130 m ² / g and use of other general light calcium carbonate) By using calcium carbonate having a small specific surface area, glossiness is reduced. Although it comes out, it is inferior in the absorbability and drying property of the inkjet ink. In addition, poor drying and fixing of ink may occur.

(Use of Light Calcium Carbonate with Specific Surface Area of 50 to 130 m ² / g) A specific surface area comparable to that of synthetic amorphous silica, and the fact that calcium carbonate has a cationic property allows ink (anion) ) Is good in fixability.

(5 to 50 parts by weight of binder with respect to 100 parts by weight of pigment)
Due to the film forming property of the binder, if the amount is too large, the formation of the porous surface is hindered, and if the amount is too small, the fixation of the pigment is deteriorated, and problems such as powder dropout occur.

(Incorporation of synthetic silica) The ink has excellent ink absorbency and drying properties, and has an effect of preventing print strikethrough due to the opacity of the pigment. Excessive content of synthetic silica impairs the appearance of gloss.

[0033]

As described above, according to the present invention, excellent ink absorbency, clear printing with almost no bleeding, extremely excellent fading resistance, and smoothness and glossiness of the recording paper surface are obtained. And cost can be reduced as compared with the case where silica is used as a pigment.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Mitsuaki Yamamoto 5-1 Kamiyacho, Iyo Mishima City, Ehime Prefecture Daio Paper Co., Ltd. (56) References JP-A-61-20797 (JP, A) JP-A-3 -284978 (JP, A) JP-A-10-851 (JP, A) JP-A-11-240243 (JP, A) JP-A-11-240248 (JP, A) JP-A-11-254806 (JP, A) JP-A-5-59694 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41M 5/00 D21H 19/38 D21H 27/00

Claims (3)

(57) [Claims] 1. The method according to claim 1, wherein at least one surface of the base paper contains 50% by weight or more of light calcium carbonate having a specific surface area of 50 to 130 m ² / g in the pigment and 100 parts by weight of the pigment.
Forming a coating layer containing 5 to 50 parts by weight of a binder
At the same time, the wet coating layer is mirror-finished and heated.
Cast coat that presses against a drum with a cylindrical outer surface
A method for producing an ink jet recording paper , comprising forming a receptor layer by a printing method . 2. A ratio method for producing an ink jet recording sheet according to claim 1, wherein the surface area containing the precipitated calcium carbonate is 50~130m ² / g in the pigment 90 wt% or more. 3. At least one surface of the base paper contains at least 50% by weight of light calcium carbonate having a specific surface area of 50 to 130 m ² / g, less than 50% by weight of synthetic silica, and an aluminum compound cation. Containing the agent
The binder is used in an amount of 5 to 50 based on 100 parts by weight of the pigment.
An ink jet recording paper comprising a receiving layer containing parts by weight.