JPH08207431A - Method for producing cast coated paper for ink jet recording, cast coated paper and recording method using the same - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a cast coated paper having an excellent white paper surface gloss and excellent ink jet recording (printing) suitability. [Structure] A cast coated paper for ink jet recording comprising a base paper provided with a coating layer containing alumina and an adhesive having a bulk density of 0.2 g / cm ³ or less, and a layer containing a resin being further cast-finished.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cast coated paper for inkjet recording, and particularly to the production of a cast coated paper for inkjet recording having excellent white paper surface gloss, excellent inkjet recording suitability and preservability of recorded images. The present invention relates to a method, a cast coated paper and a recording method thereof.

[0002]

2. Description of the Related Art In recent years, recording by an ink jet printer has been used in various fields because of its low noise, high speed recording, and easy multicoloring. As the paper for inkjet recording, high-quality paper devised so as to have high ink absorbability, coated paper having a surface coated with a porous pigment, and the like are applied. By the way, all of these papers are mainly so-called matte ink jet recording papers having low surface gloss.

However, recently, with the expansion of applications such as speeding up of ink jet recording, high definition of recorded images, and full-colorization, ink jet recording papers having high surface gloss and excellent appearance characteristics have been demanded. Generally, as a paper with a high surface gloss, a coated paper having a high gloss obtained by applying a plate-like pigment on the surface and, if necessary, applying a pressure treatment with a calender, or a wet coating layer is used. There is known a so-called cast coated paper or the like obtained by copying the mirror surface by pressing and drying it on a heating drum surface having a mirror surface.

In general, cast coated paper has high surface gloss and superior surface smoothness as compared with ordinary coated paper which is pressure-finished by a super calender, and exhibits an excellent printing effect. Therefore, although it is exclusively used for applications such as high-quality printed matter, when it is used as an inkjet recording medium, it has various difficulties.

That is, in general, cast coated paper has a high gloss because a film-forming substance such as an adhesive in the pigment composition constituting the coated layer copies the specular drum surface of the cast coater. On the other hand, the presence of the film-forming substance causes a problem that the coating layer loses its porosity and the ink absorption during ink jet recording is extremely reduced. In order to improve the ink absorbency, it is important to make the cast coating layer porous so that the ink can be easily absorbed. For that purpose, it is necessary to reduce the amount of film-forming substance. Becomes On the other hand, by reducing the amount of the film-forming substance, the glossiness of white paper is reduced as a result. Thus, it was extremely difficult to satisfy both the surface gloss of the cast coated paper and the suitability for inkjet recording (printing) at the same time.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a cast coating which maintains the original high smoothness and excellent glossiness of the cast coated paper and exhibits extremely excellent ink jet printing recording suitability and excellent recorded image storability. Provided are a method for manufacturing a coated paper, a cast coated paper, and a recording method thereof.

[0007]

The present invention includes, but is not limited to, the following aspects. [1] In the present invention, the bulk density (JIS H-190
2) is a coating layer containing alumina and an adhesive having a content of 0.2 g / cm ³ or less, and the coating layer for casting is formed by coating a coating liquid containing a resin on the coating layer. A method for producing cast coated paper for ink-jet recording, which comprises press-contacting a heated mirror-finished drum in a wet state and drying to finish.

[2] The BET specific surface area of alumina is 20
The method for producing a cast coated paper for inkjet recording according to [1], which has a content of 0 m ² / g or less.

[3] The resin is preferably a resin obtained by polymerizing a monomer having an ethylenically unsaturated bond. Further, the method for producing a cast coated paper for inkjet recording described in [1] or [2], which is a resin having a glass transition point of 40 ° C. or higher, is preferable.

[4] Bulk density (JIS H-190
2) A coating layer containing alumina and an adhesive having a content of 0.2 g / cm ³ or less is provided, and a coating liquid containing a resin is further applied to the coating layer to obtain a cast layer. Cast coated paper for inkjet recording.

[5] The BET specific surface area of alumina is 200
The cast coated paper for inkjet recording according to [4], which has a m ² / g or less.

[6] The cast coated paper for ink jet recording according to [4], wherein the resin is a resin obtained by polymerizing a monomer having an ethylenically unsaturated bond and has a glass transition point of 40 ° C. or higher.

[7] An ink jet recording method for forming an image on a cast coated paper for ink jet recording according to claim 4 by ejecting a water-based ink from fine pores.

[8] The ink jet recording method according to [7], wherein heat energy is applied to the water-based ink to eject the ink.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the alumina contained in the undercoating layer, which is important for obtaining desired properties as product quality, will be described. In the case of conventional ink jet recording paper, silica-based pigments have been mainly used for the purpose of obtaining high properties in terms of acceptability of ink, clearness of print recording, high print density, color developability, and gradation. However, the silica-based pigment is accompanied by the drawback that the recorded image is likely to be discolored or fading when exposed to oxygen in the air or sunlight.

The inventors of the present invention have made extensive studies to improve various quality characteristics which the conventional ink jet recording paper as described above has as a difficulty. As a result, the ink receiving layer of the coated paper for inkjet recording has a two-layer structure, and as a pigment to be contained in the undercoat layer therein, a low bulk density having a bulk density (JIS H-1902) of 0.2 g / cm ³ or less. It has been found that when alumina is used and a cast coating layer is formed thereon, the above-mentioned problems are all solved or alleviated, and particularly excellent storage stability and excellent gloss and image quality can be obtained. The lower limit of the bulk density of alumina is not particularly limited, but is preferably 0.04 or more, more preferably 0.05 to 0.15.

The bulk density of the present invention is JIS H-1902.
The same as the bulk specific gravity by g / cm ³ as a unit
Is attached. Alumina often has a plate-like structure, but scaly alumina is preferable because voids are easily included between particles. In addition, the commercially available alumina has a bulk density of 0.4 g / cm ³ or more, and most of them have a bulk density of 0.6 to
It is about 1.5 g / cm ³ .

As described above, the reason why the preferable results are obtained by using the low bulk density alumina is not always clear, but the use of the low bulk density alumina makes the undercoat layer very porous. It is presumed that the shape can be developed, and thereby the absorbability of the ink is improved.

The present invention is characterized by using alumina having the above bulk density. The method for producing alumina is not particularly limited. However, according to the hydrolysis method of aluminum alkoxide illustrated in FIG. 5, fine-grained high-purity alumina is obtained. That is, it is a method in which metallic aluminum is reacted with an alcohol such as methanol to produce an aluminum alkoxide, which is then hydrolyzed to obtain aluminum hydroxide and further calcined to obtain alumina.

As a method for producing low bulk density alumina
Is not particularly limited, but the temperature during firing, the time
Or conditions such as the type of hydrated alumina used as the raw material
Can be combined appropriately and adjusted to the desired bulk density
It Among the low bulk density alumina as described above, preferably
BET specific surface area is 200m ²/ G or less. This
Inkjet recording, the preservation of printed images
Weatherability) is further improved. BET specific surface area is
Direct reading type BET specific surface area measuring device Monosorb manufactured by Chrome Co.
By BET 1 point method.

The lower limit of the BET specific surface area is not particularly limited, but usually 1.0 m ² / g or more is preferable. Further, if it is too low, the ink absorbability may decrease. Therefore, it is more preferably 10 m ² / g or more, still more preferably 100 m ² / g.
That is all. The BET specific surface area is influenced by the shape of the alumina primary particles. There is no correlation between the bulk density and the BET specific surface area. The average particle size of the primary particles of alumina is not particularly limited, but it is 0.01 to 1 μm according to an electron micrograph.
It is a degree. However, the particle size distribution is about 0.05 to 10 μm as measured by another method such as the sedimentation method because of the secondary aggregation, but this value changes depending on the dispersion method of the pigment dispersion liquid. That is, the dispersion state changes depending on the slurry concentration, the presence or absence of the dispersant, the type of the disperser, and the change with time after the slurry is prepared. In the case of cationic alumina (Sumitomo Chemical Co., Ltd., trade name: AKP-G015), the primary particles are 0.1 μm.
As shown below, when about 0.8% by weight of alumina is ultrasonically dispersed in a 0.2% by weight sodium hexametaphosphate solution for 10 minutes, the average particle size is about 2 μm, and the particles are dispersed with a high dispersion type sand mill. When it does, it becomes about 0.5 μm.

The above-mentioned alumina is preferably contained in an amount of 50 to 100% by weight based on all pigments in the undercoat layer. Other pigments, if necessary, generally used in the coated paper manufacturing field, such as kaolin, clay, calcined kaolin,
Amorphous silica, zinc oxide, aluminum hydroxide, calcium carbonate, satin white, aluminum silicate, magnesium silicate, magnesium carbonate, plastic pigment and the like can be appropriately used.

The reason why the specific alumina of the present invention is contained as an essential component particularly in the undercoat layer is that when it is contained in a large amount in the cast coating layer, the color developability of the ink and the surface gloss of the cast paper are reduced. It may occur.

Next, as the adhesive used in combination with the alumina, proteins such as casein, soybean protein, and synthetic protein,
Various starches such as starch and oxidized starch, polyvinyl alcohol, cellulose derivatives such as carboxymethyl cellulose and methyl cellulose, styrene-butadiene copolymer,
Methyl methacrylate-butadiene copolymer conjugated diene polymer latex, acrylic polymer latex,
Conventionally known adhesives generally used for coated paper such as vinyl polymer latex such as ethylene-vinyl acetate copolymer are used alone or in combination of two or more kinds. The amount of the adhesive compounded is 100 parts by weight of the pigment,
It is adjusted in the range of 5 to 50 parts by weight, more preferably 10 to 30 parts by weight.

To the coated paper for ink jet recording, a cationic resin can be added to the coated layer for the purpose of improving the water resistance and the color density of printing. In the present invention, it is particularly preferable to add it to the above-mentioned alumina-containing layer. As the cationic resin in this case, for example, polyalkylene polyamines such as polyethylene polyamine or polypropylene polyamine, or a derivative thereof, an acrylic resin having a tertiary amino group or a quaternary ammonium group, a diacrylamine, etc. are appropriately used. Also, two or more kinds may be used in combination.

The addition amount of the cationic resin is not particularly limited, but is 1 to 30% by weight, preferably 5% by weight with respect to the pigment.
It is adjusted in the range of 20% by weight. In addition, various auxiliaries such as a dispersant, a thickener, an antifoaming agent, a colorant, an antistatic agent and an antiseptic agent used in the production of general coated paper can be appropriately added.

The composition of the undercoat layer composed of the above-mentioned materials is generally adjusted to a solid content concentration of about 1 to 65% by weight, and the base paper has a basis weight of about 20 to 400 g / m ^{2. 2} to 50 g / m ² in dry weight, preferably 5 to
20 g / m ² about to become as blade coater, air knife coater, roll coater, brush coater,
It is coated and dried by a coating device such as a Champlex coater, a bar coater, or a gravure coater. further,
If necessary, smoothing treatment such as super calendering, brushing, and cast finishing can be performed after the undercoat coating layer is dried.

The base paper to be the support is not particularly limited, and acidic paper or neutral paper used for general coated paper is appropriately used.

The bulk density thus formed is 0.2 g
As the resin to be contained in the coating layer for casting, which is provided on the alumina-containing layer having a density of not more than / cm ³ , a polymer obtained by polymerizing a monomer having an ethylenically unsaturated bond can be exemplified. That is, as a polymer obtained by polymerizing a monomer having an ethylenically unsaturated bond (hereinafter referred to as an ethylenic monomer), for example, methyl acrylate, ethyl acrylate, butyl acrylate, 2 ethylhexyl acrylate, lauryl acrylate, 2-hydroxyethyl acrylate, Alkyl group such as glycidyl acrylate having 1 to 18 carbon atoms, alkyl methacrylate such as methyl methacrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, glycidyl methacrylate having 1 to 18 carbon atoms Methacrylic acid ester, styrene, α-methylstyrene, vinyltoluene, acrylonitrile, vinyl chloride, vinylidene chloride, vinyl acetate, vinyl propionate, acrylic amine , N- methylol acrylamide, ethylene, polymer obtained by polymerizing the ethylenic monomers such as butadiene.

Incidentally, the polymer in this case may be a copolymer in which two or more kinds of ethylenic monomers are used in combination, and further, these polymers or a substituted derivative of the copolymer may be used. . Incidentally, examples of the substituted derivative include a carboxyl group derivative and an alkali derivative thereof. It is also possible to polymerize the above-mentioned monomer having an ethylenically unsaturated bond in the presence of colloidal silica and use it in the form of a complex by Si—O—R (R: polymer component) bond. . Further, a pigment such as colloidal silica may be added in an amount of, for example, about 200 parts by weight or less relative to 100 parts by weight of the resin as long as the glossiness and the recording suitability are not impaired. The particle size of colloidal silica is not particularly limited, but the average particle size is 0.
It is preferably about 01 to 0.2 μm.

The polymer (resin) contained in the above coating layer for casting preferably has a glass transition point of 40 ° C. or higher. More preferably, it is about 50 to 100 ° C.

That is, in the conventional production of cast coated paper, in order to obtain an excellent surface gloss, the resin (polymer) in the cast coating composition should be sufficiently formed into a film during the casting finish. , Had obtained a high gloss. However, in such a conventional method, the porosity of the surface of the cast coating layer is reduced, and as a result, the absorbability of the ink during inkjet recording is reduced, and a cast coated paper having desirable inkjet recording suitability is obtained. Often difficult to do.

Therefore, in order to make the ink absorbability more excellent, a polymer having a relatively high glass transition point is used, and cast finishing is carried out in a state where the polymer does not completely form a film. It is preferable. As a result, the porosity of the surface of the cast coated paper is effectively maintained, and a cast coated paper having excellent ink absorption and an excellent glossy surface can be obtained.

On the other hand, when the glass transition point of the polymer is low, the heat of the surface of the cast drum facilitates the film formation of the resin component more than necessary, resulting in a decrease in the porosity of the surface of the cast coating layer. Although the surface has a high gloss value, there is a risk that the ink absorbency will decrease. Therefore, in the present invention, it is preferable to dry finish the cast coated layer under the temperature condition below the glass transition point of the resin contained in the cast coated layer during the production of the cast coated paper.

In order to adjust the whiteness, viscosity, fluidity, etc., of the cast coating layer, pigments, dispersants, and thickeners used in general printing coated paper and ink jet recording paper are used. Various auxiliaries such as agents, defoaming agents, coloring agents, antistatic agents and preservatives can be appropriately added.

On the coated surface of the undercoat coated paper, a cast coating liquid containing the above-mentioned polymer is applied to a blade coater, an air knife coater, a roll coater, a brush coater, a chanplex coater, a bar coater, a gravure coater, etc. The coating is carried out by various known coating devices described in 1 above, and while the coating layer is in a wet state as described above, it is pressed against a heated mirror-finished drum and dried to perform a cast finish. The coating amount of the cast coating liquid in this case is 0.2 to 30 g / m ² in terms of dry solid content, preferably 1 to 10 g / m ² .
m ² . In a preferred embodiment of the present invention, the cast paper is 300 seconds / 100 cc or less, more preferably 10 to 100 cc.
Air permeability of 200 seconds / 100 cc (JIS-P-811
It is adjusted to 7), but this makes it possible to obtain a recording material having a better ink absorbency. In addition, the Gurley air permeability after forming the undercoat layer (ASTM-D-
726 B method) is preferably 30 seconds / 10 cc or less.

The ink jet recording method of the present invention using the thus obtained cast coated paper for ink jet recording may be a system capable of effectively separating the ink from the nozzle to apply the ink to the recording medium as a range. Any method may be used, but in particular, in the method described in JP-A-54-59936, the ink subjected to the action of thermal energy undergoes a rapid volume change, and the action force due to this state change causes An inkjet recording method in which ink is ejected from nozzles can be effectively used.

An example of an inkjet recording apparatus suitable for the inkjet recording method of the present invention will be described below. An example of the head structure, which is the main part of the apparatus, is shown in FIGS. 1, 2 and 3. That is, the head 13 is made of glass, ceramic, plastic plate, or the like having a groove 14 through which ink passes, and a heating head 15 (a head is shown in the drawing, but not limited to this) used for thermal recording. It is obtained by bonding. The heating head 15 includes a protective film 16 made of silicon oxide or the like and aluminum electrodes 17-1 and 17.
-2, a heating resistor layer 18 made of nichrome or the like, a heat storage layer 19, and a substrate 20 having a good heat dissipation property such as alumina.

The ink 21 has a discharge orifice (fine hole) 2
2, the meniscus 23 is formed by the pressure P.

Now, when an electric signal is applied to the electrodes 17-1 and 17-2, the area indicated by n of the heating head 15 rapidly generates heat, and bubbles are generated in the ink 21 in contact therewith, and the pressure thereof is generated. At this point, the meniscus 23 is projected, the ink 21 is ejected, becomes a recording droplet 24 from the orifice 22, and flies toward the recording sheet 25. FIG. 3 shows an external view of a multi-head in which many heads shown in FIG. 1 are arranged. The multi-head includes a glass plate 27 having multi-grooves 26, and FIG.
The heating head 28 similar to that described in FIG.

FIG. 1 shows the head 1 along the ink flow path.
3 is a sectional view of FIG. 3, and FIG. 2 is a sectional view taken along the line AB of FIG. 1.

FIG. 4 shows an example of an ink jet recording apparatus incorporating such a head. In FIG. 4, 61
Is a blade serving as a wiping member, one end of which is held by a blade holding member to be a fixed end, which is in the form of a cantilever. The blade 61 is arranged at a position adjacent to the recording area by the recording head, and in the case of this example, is held in a form protruding in the movement path of the recording head. Reference numeral 62 denotes a cap, which is disposed at a home position adjacent to the blade 61, and has a configuration in which it moves in a direction perpendicular to the moving direction of the recording head and contacts the ejection port surface to perform capping. Further, 63 is an ink absorber provided adjacent to the blade 61, and is held in a form projecting in the movement path of the recording head like the blade 61. The blade 61, the cap 62, and the absorber 63 form an ejection recovery unit 64, and the blade 61 and the absorber 63 remove water, dust, and the like from the ink ejection port surface.

Reference numeral 65 denotes a recording head having ejection energy generating means, which ejects ink onto a recording medium facing the ejection port surface where ejection ports are arranged for recording, and 66 denotes a recording head 65 having the recording head 65 mounted thereon. It is a carriage for moving the. The carriage 66 slidably engages with a guide shaft 67, and a part of the carriage 66 is connected (not shown) to a belt 69 driven by a motor 68. Accordingly, the carriage 66 can move along the guide shaft 67, and the recording area by the recording head 65 and the area adjacent thereto can be moved.

Reference numeral 51 designates a paper feed section for inserting a recording medium, and 5
A paper feed roller 2 is driven by a motor (not shown). With these configurations, the recording medium is fed to a position facing the ejection opening surface of the recording head, and is ejected via the ejection roller 53 as the recording progresses.

In the above configuration, when the recording head 65 returns to the home position after the recording is completed, the head recovery unit 6
The fourth cap 62 is retracted from the movement path of the recording head 65, but the blade 61 is projected in the movement path. As a result, the ejection port surface of the recording head 65 is wiped. When the cap 62 comes into contact with the protruding surface of the recording head 65 to perform capping, the cap 62 moves so as to protrude into the movement path of the recording head.

When the recording head 65 moves from the home position to the recording start position, the cap 62 and the blade 61 are in the same positions as the above wiping positions. As a result, the protruding opening surface of the recording head 65 is wiped even during the movement.

The above-mentioned movement of the recording head to the home position is performed not only at the end of recording and at the time of ejection recovery, but also at the home adjacent to the recording area at a predetermined interval while the recording head moves in the recording area for recording. After moving to the position, the wiping is performed in accordance with the movement.

On the other hand, in the ink used in the ink jet recording method of the present invention, a dye for forming an image and a liquid medium for dissolving or dispersing the dye are essential components,
If necessary, various dispersants, surfactants, viscosity modifiers,
It is prepared by adding a specific resistance adjusting agent, a pH adjusting agent, an antifungal agent, a dissolution (or dispersion) stabilizer of a recording agent, and the like.

The recording agents used in the ink include direct dyes, acid dyes, basic dyes, reactive dyes, food dyes, disperse dyes, oil dyes and various pigments, but conventionally known ones are not particularly limited. Can be used without. The content of such a dye is determined depending on the type of liquid medium component, the properties required for the ink, etc., but in the case of the ink of the present invention, the formulation as in the conventional ink, that is, There is no particular problem when used in a proportion of about 0.1 to 20% by weight. Alumina having a specific bulk density used in the present invention is preferably cationic,
In this case, it is particularly preferable to use a direct dye or an acid dye as the dye from the viewpoints of color developability and light resistance.

The ink used in the present invention is a liquid solvent in which the above dye is dissolved or dispersed, and a polyhydric alcohol having an effect of preventing the ink from drying is used as water or water and a water-soluble organic solvent. What is contained is used. The preferable range of the surface tension of the yellow, cyan, and magenta color inks used in the present invention is 25-40.
The range is dyne / cm, and this range is effective in suppressing ink bleeding between different colors.

[0051]

The present invention will be described in more detail with reference to the following examples, but of course the present invention is not limited thereto. Unless otherwise specified, parts and% in the examples represent parts by weight and% by weight, respectively.

Example 1 As a pigment, high purity alumina (manufactured by Sumitomo Chemical Co., Ltd.,
Product name: AKP-G015, scaly alumina, bulk density 0.07 g / cm ³ , specific surface area 150 m ² / g) 100
Parts, 15 parts of polyvinyl alcohol as an adhesive, 8 parts of polyethylene polyamine-based resin as a cationic resin,
Condensate resin of dicyandiamide and formalin (trade name:
Neofix FY / manufactured by Nichika Chemical Co., Ltd.) 10 parts,
As a dispersant, 0.5 part of sodium polyphosphate was added to prepare an undercoating coating liquid having a solid content concentration of 15%. This undercoat coating liquid was applied to a base paper of 100 g / m ² of tsubo in a dry weight of 8
Coat with an air knife coater to achieve g / m ² ,
A base paper for undercoating was obtained by drying.

On the other hand, as a cast coating liquid, 40 parts of a styrene-2 methylhexyl acrylate copolymer having a glass transition point of 80 ° C., 60 parts of colloidal silica, and 2 parts of calcium stearate as a release agent have a solid content concentration of 30.
% Coating solution for casting was prepared. This coating liquid was coated on the above-mentioned undercoat base paper using a roll coater, immediately followed by pressure contact with a mirror surface drum having a surface temperature of 85 ° C., drying and release to obtain a cast coated paper for inkjet recording. It was The coating amount at this time was 7 g / m ² in terms of solid content weight.

Example 2 In the same manner as in Example 1, except that the surface temperature of the specular drum was changed from 85 ° C. to 70 ° C. in obtaining the cast coated paper in Example 1, the cast coated paper for ink jet recording was performed. Got The coating amount at this time is 7% by weight of solid content.
It was g / m ² .

Example 3 100 parts of a styrene-methyl acrylate copolymer having a glass transition point of 50 ° C. as a cast coating liquid and 5 parts of ammonium oleate as a releasing agent, the solid content concentration was 35.
% Coating solution for casting was prepared. This coating liquid was coated on the base paper for undercoat obtained in Example 1 by using a roll coater, and immediately thereafter, it was pressed against a mirror surface drum having a surface temperature of 60 ° C., dried and then released, and cast coating for inkjet recording. I got the paper. The coating amount at this time is 3 g in terms of solid content weight.
/ M ² .

Example 4 100 parts of a composite of a styrene-methyl acrylate copolymer having a glass transition point of 70 ° C. and colloidal silica (weight ratio 50:50) as a cast coating liquid, and 3 parts of ammonium oleate as a releasing agent. A coating liquid for casting having a solid content concentration of 40% was prepared. This coating liquid was applied onto the base paper for undercoat obtained in Example 1 by using a roll coater, and immediately thereafter, it was pressed against a heating mirror surface drum having a surface temperature of 65 ° C., dried, and then released for inkjet recording. A cast coated paper was obtained. The coating amount at this time is the solid content weight,
It was 6 g / m ² .

Example 5 As a pigment, high-purity alumina (manufactured by Sumitomo Chemical Co., Ltd., trade name: AKP-G030, scaly alumina, bulk density 0.07 g / cm ³ , specific surface area 250 m ² / g) 9
0 parts, and 10 parts of amorphous silica, 15 parts of polyvinyl alcohol as an adhesive, 8 parts of polyethylene polyamine resin as a cationic resin, a condensate resin of dicyandiamide and formalin (trade name: Neofix FY / Nika Chemical Industry ( (Manufactured by K.K.) and 0.5 part of sodium polyphosphate as a dispersant were added to prepare a coating liquid for undercoating having a solid content concentration of 15%. This undercoat coating liquid
g / m ² of the base paper so that the dry weight becomes 8 g / m ² .
It was coated with an air knife coater and dried to obtain a base paper for undercoating.

Then, the undercoat base paper was coated with the casting coating solution used in Example 1 to obtain a cast coated paper for ink jet recording in the same manner as in Example 1. The coating amount at this time was 7 g / m ² in terms of solid content weight.

Example 6 In obtaining the cast coated paper in Example 1, high-purity alumina (manufactured by Sumitomo Chemical Co., Ltd., trade name: AKP) was used.
-G015, bulk density 0.07 g / cm ³ , specific surface area 15
0 m ² / g) 100 parts of high-purity alumina (Sumitomo Chemical Co., Ltd., trade name: AKP-G, plate-like alumina, bulk density 0.18 g / cm ³ , specific surface area 150 m ² / g) 10
A cast coated paper for ink jet recording was obtained in the same manner except that the content was 0 part.

Comparative Example 1 MgCO ₃ (bulk density 0.2
70 parts of 6 g / cm ³ , specific surface area 50 m ² / g, heavy calcium carbonate (bulk density 1.1 g / cm ³ , specific surface area 3.
0 m ² / g) 30 parts, adhesive starch 5 parts, styrene-butadiene copolymer latex 10 parts, dicyandiamide and formalin condensate resin (trade name: Neofix FY / Nika Chemical Industry Co., Ltd.) )
5 parts) and 0.4 parts of sodium polyphosphate as a dispersant were added to prepare an undercoating coating solution having a solid content concentration of 30%. This undercoating coating liquid was coated on a base paper having a basis weight of 100 g / m ² to a dry weight of 15 g / m ² with a blade coater and dried to obtain an undercoat base paper.

Then, the undercoat base paper was coated with the casting coating solution used in Example 1 to obtain a cast coated paper for ink jet recording in the same manner as in Example 1. The coating amount at this time was 6 g / m ² in terms of solid content weight.

Comparative Example 2 High-purity alumina (trade name: AKS-G, plate-shaped alumina, manufactured by Sumitomo Chemical Co., Ltd.) as a pigment for the undercoat coating liquid.
Bulk density 0.4 g / cm ³ , specific surface area 150 m ² / g) 1
00 parts, polyvinyl alcohol 15 parts as an adhesive, polyethylene polyamine resin as a cationic resin (trade name: Neofix RP-70 / Nika Chemical Industry Co., Ltd.)
8 parts) and 0.4 parts of sodium polyphosphate as a dispersant were added to prepare an undercoating coating liquid having a solid content concentration of 20%. This undercoating coating liquid was applied to a base paper having a basis weight of 80 g / m ² by an air knife coater so as to have a dry weight of 7 g / m ² , and dried to obtain an undercoating base paper.

The undercoat base paper was coated with the casting coating liquid used in Example 1 to obtain a cast coated paper for ink jet recording in the same manner as in Example 1. The coating amount at this time was 7 g / m ² in terms of solid content weight.

Comparative Example 3 Amorphous silica (bulk density 0.05 g / cm ³ , specific surface area 250 m ² / g) 100 was used as a pigment for the undercoating liquid.
Parts, 15 parts of polyvinyl alcohol as an adhesive, 8 parts of diacrylamine acrylamide resin (trade name: Sumirez Resin 1001 / Sumitomo Chemical Co., Ltd.) as a cationic resin, and 0.4 parts of sodium polyphosphate as a dispersant. Then, an undercoating coating liquid having a solid content of 30% was prepared. This coating liquid was coated on a base paper having a basis weight of 80 g / m ² by a blade coater so as to have a dry weight of 6 g / m ^2, and dried to obtain an undercoat base paper. The undercoat base paper was coated with the casting coating liquid used in Example 1 to obtain an inkjet recording cast coated paper in the same manner as in Example 1. The coating amount at this time was 5 g / m ² in terms of solid content weight.

Comparative Example 4 In Comparative Example 2, high-purity alumina (manufactured by Sumitomo Chemical Co., Ltd., trade name: AKS-G) in the coating liquid for undercoating was used.
0 parts of high-purity alumina (Sumitomo Chemical Co., Ltd., trade name: AKP-3000, plate-like alumina, bulk density 0.7
g / cm ³ , specific surface area 6 m ² / g) A cast coated paper for inkjet recording was obtained in the same manner except that the amount was 100 parts.

Comparative Example 5 In Comparative Example 2, 100 parts of high-purity alumina (AKS-G manufactured by Sumitomo Chemical Co., Ltd.) in the coating liquid for undercoating was converted from alumina obtained by treating bauxite with hot caustic soda (Sumitomo Chemical Industry Co., Ltd., trade name: A-1
1. A cast coated paper for ink jet recording was obtained in the same manner except that 1, plate-like alumina, bulk density 1.1 g / cm ³ , specific surface area 150 m ² / g) was 100 parts.

Comparative Example 6 As a pigment, 50 parts of kaolin (bulk density 0.85 g / cm ³ , specific surface area 20 m ² / g), light calcium carbonate (bulk density 0.8 g / cm ³ , specific surface area 11.5 m ² / g) 5
0 parts, 5 parts of oxidized starch as an adhesive, 20 parts of styrene-butadiene copolymer latex, and 0.5 parts of sodium polyphosphate as a dispersant were added to prepare an undercoating coating solution having a solid content of 50%. This undercoat coating liquid, 100 g of tsubo
/ M ² base paper so that the dry weight is 12 g / m ² ,
It was coated with an air knife coater and dried to obtain a base paper for undercoating.

Kaolin 100 is used as a cast coating liquid.
Parts, casein 10 parts, styrene having a glass transition point of 30 ° C.
A coating liquid for casting having a solid content concentration of 45%, which was composed of 10 parts of methyl methacrylate and 10 parts of calcium stearate as a release agent, was prepared and coated on the above-mentioned undercoat base paper using a roll coater, and immediately thereafter the surface was immediately coated. Temperature is 85
It was pressed against a mirror surface drum at ℃, dried, and then released to obtain a cast coated paper for inkjet recording. The coating amount at this time was 12 g / m ² in terms of solid content weight.

The results of white gloss, ink jet recording suitability, and weather resistance of the cast coated paper thus obtained are summarized in Table 1. The above evaluation was carried out by the following method.

(Brightness of white paper) It was measured according to JIS-P8142.

(Absorbability of ink jet recording ink)
Yellow, cyan, and magenta color inks containing a direct dye and having a surface tension of 35 dyne / cm were mounted on a bubble jet printer BJC600 (trade name) manufactured by Canon to perform printing, and the quick drying property of the ink was visually evaluated. ⊚: Ink is absorbed within 1 second after printing, and the boundary between the green portion, which is a mixed color portion of magenta and cyan, and the red portion, which is a mixed color portion of yellow and magenta, is clear. ◯: The ink is absorbed within 5 seconds of printing, and the boundary between the green part and the red part is clear. Δ: Ink absorption exceeds 5 seconds after printing, but the boundary between the green part and the red part is clear. X: Absorption of ink exceeds 20 seconds, and the boundary between the green part and the red part is slightly unclear. XX: Ink absorption exceeds 1 minute, the boundary between the green and red parts is unclear, and the boundary between the magenta, cyan, and yellow parts is slightly unclear.

(Coloring property of ink jet recording ink after recording) Bubble jet printer BJC600 described above.
Printing was carried out with and the ink density was visually evaluated. This evaluation reflects the sharpness in color recording. ◯: The color density is excellent. Δ: Color density is slightly low.

(Weather resistance) After left at room temperature for 3 months, the decrease in print density was visually determined. ◯: Good, with no decrease in print density. Δ: A decrease in print density is recognized. X: The print density is remarkably reduced.

[0074]

[Table 1]

[0075]

As is clear from the results of Table 1, the cast coated paper of the present invention was excellent in surface glossiness, ink jet recording suitability and weather resistance, and could be efficiently produced.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a head portion of an inkjet recording apparatus.

FIG. 2 is a cross-sectional view of a head portion of an inkjet recording device.

3 is an external perspective view of a head in which the head shown in FIG.

FIG. 4 is a perspective view showing an example of an inkjet recording apparatus.

FIG. 5 illustrates a method for producing alumina by a hydrolysis method of aluminum alkoxide.

[Explanation of symbols]

 13: Head 14: Groove through which ink is passed 15: Heating head 16: Protective film 17-1: Aluminum electrode 17-2: Aluminum electrode 18: Heating resistor layer 19: Heat storage layer 20: Substrate 21: Ink 22: Orifice 23: Meniscus 24: Recording droplets 25: Recording sheet 26: Multi-groove 27: Glass plate 28: Heating head 51: Paper feeding section 52: Paper feeding roller 53: Paper discharging roller 61: Blade 62: Cap 63: Ink absorber 64: Discharge recovery unit 65: Recording head 66: Carriage 67: Guide shaft 68: Motor 69: Belt

Continued Front Page (72) Inventor Hiroyuki Ohashi 4-3-1, Jokoji, Amagasaki, Hyogo Pref., Kanzaki Mill, Shin Oji Paper Co., Ltd. (72) Inventor Kazuhiro Nojima 4-3-1, Jokoji, Amagasaki, Hyogo Shin-Oji Paper Co., Ltd. Kanzaki Mill (72) Inventor Mamoru Sakaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Keiichi Suzuki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (8)

[Claims] 1. A base paper is provided with a coating layer containing alumina and an adhesive having a bulk density (JIS H-1902) of 0.2 g / cm ³ or less, and a coating layer containing a resin. A method for producing a cast coated paper for ink jet recording, which comprises press-coating a heated mirror surface drum and drying to finish while a coating layer for casting formed by coating a liquid is in a wet state. 2. Alumina has a BET specific surface area of 200 m ² /
The method for producing a cast coated paper for inkjet recording according to claim 1, which is not more than g. 3. The cast coated paper for inkjet recording according to claim 1, wherein the resin is a resin obtained by polymerizing a monomer having an ethylenically unsaturated bond and has a glass transition point of 40 ° C. or higher. Manufacturing method. 4. A base paper is provided with a coating layer containing alumina and an adhesive having a bulk density (JIS H-1902) of 0.2 g / cm ³ or less, and a coating layer containing a resin in the coating layer. A cast coated paper for inkjet recording, which is obtained by casting a layer obtained by coating a liquid. 5. The BET specific surface area of alumina is 200 m ² /
The cast coated paper for ink jet recording according to claim 4, which is not more than g. 6. The cast coated paper for ink jet recording according to claim 4, wherein the resin is a resin obtained by polymerizing a monomer having an ethylenically unsaturated bond and having a glass transition point of 40 ° C. or higher. 7. An ink jet recording method for forming an image on a cast coated paper for ink jet recording according to claim 4 by ejecting a water-based ink from fine pores. 8. The ink jet recording method according to claim 7, wherein heat energy is applied to the water-based ink to eject the ink.